Transmission Flange Oil Leak From Split Pin

[yianni]

After car sat for most of the winter, I noticed an oil leak. After investigation, it is coming from transmission right flange split pin. Has anyone had this problem or have advice for how to correct. I have attached two pics to show seals are dry and clean. Thanks in advance for any responses.

[PJ Grady Inc.]

It is highly unusual for a leak from the pin area unless an incorrect oring has been fitted. That is a problem common to Lotus Esprit UN1's but not the DMC UN1 due to a different axle configution. I notice that an aftermarket oil seal has been fitted. Are you positive about the seal not leaking? We carry OEM seals and stainless sleeved axle flanges if you need them.
Rob

QUOTE=yianni;168599]After car sat for most of the winter, I noticed an oil leak. After investigation, it is coming from transmission right flange split pin. Has anyone had this problem or have advice for how to correct. I have attached two pics to show seals are dry and clean. Thanks in advance for any responses.[/QUOTE]

[yianni]

It is highly unusual for a leak from the pin area unless an incorrect oring has been fitted. That is a problem common to Lotus Esprit UN1's but not the DMC UN1 due to a different axle configution. I notice that an aftermarket oil seal has been fitted. Are you positive about the seal not leaking? We carry OEM seals and stainless sleeved axle flanges if you need them.
Rob

QUOTE=yianni;168599]After car sat for most of the winter, I noticed an oil leak. After investigation, it is coming from transmission right flange split pin. Has anyone had this problem or have advice for how to correct. I have attached two pics to show seals are dry and clean. Thanks in advance for any responses.[/QUOTE]

Thanks for the response. Leak is definitely not from seal. I wiped it a couple of times and watched it drip from inside the split pin. Seal and stainless sleeves were purchased from DMC. What puzzles me is the amount of transmission oil that has leaked out. I would estimate about 1/3 a cup. Any other ideas out there? Thanks.

[David T]

Thanks for the response. Leak is definitely not from seal. I wiped it a couple of times and watched it drip from inside the split pin. Seal and stainless sleeves were purchased from DMC. What puzzles me is the amount of transmission oil that has leaked out. I would estimate about 1/3 a cup. Any other ideas out there? Thanks.[/QUOTE]

As Rob said, typically the seal leaks, not the pin. What you *could* do is what they do on the Lotus, silicone the pin. Try replacing the "O" ring first.When you are done make sure you have enough and the correct oil in the transmission.

[Nicholas R]

Thanks for the response. Leak is definitely not from seal. I wiped it a couple of times and watched it drip from inside the split pin. Seal and stainless sleeves were purchased from DMC. What puzzles me is the amount of transmission oil that has leaked out. I would estimate about 1/3 a cup. Any other ideas out there? Thanks.

As Rob said, typically the seal leaks, not the pin. What you *could* do is what they do on the Lotus, silicone the pin. Try replacing the "O" ring first.When you are done make sure you have enough and the correct oil in the transmission.[/QUOTE]

If it doesn't leak out the pin, it will still leak past the splines (as it already has) and into the axle flange. The pin is just the first place in line for the fluid to leak out, but not the last. If you're going to silicone the pin, you would also need to remove the half shaft and silicone the splines at the end to have any real effect. It's messy, bad practice, and will certainly not fix the problem, but it may be a stall. However, for all that trouble you should just change the o-ring.

[DMCMW Dave]

I agree - I suspect that the o-ring is chipped or damaged in some way. If the seal or sleeve was bad it would leak from the seal. My bet is when you remove the axle the void between the axle and flange will be oily. It should be dry.

[Delorean Industries]

Silicone on the pin will force it into the area between the hub flange and axle. O ring is the only solution.

[yianni]

Thank you everyone for all the good advice, O ring will be changed.

[jwrayth]

As an aside to this, I replaced my leaky seals last summer and observed the same behaviour. I replaced the O-Ring at the same time as doing the seals though, and it's still leaking past. I've been intending to pull it and investigate, but now someone else is experiencing it the exact same I wonder if there is an issue with the NOS O-rings?

For replacing the O-rings I lubricated them with some fresh gearbox oil before fitting. Is there some other trick required?

[Bitsyncmaster]

I remember a trick that was done back in the old days to get better seals on shafts. That was to put a diagonal finish on the shaft where the seal sits with some fine sand paper. That minor scratching would keep any oil from getting through the seal.

[SS Spoiler]

If you run the scratches the right way, will it push oil back in?

[Bitsyncmaster]

If you run the scratches the right way, will it push oil back in?

Yes, that is the idea. You need to know the rotation direction and make the scratches so it pushes the oil back. Also the none polished surface tend to help keep the oil from flowing via surface tension. I have not looked for this info on the internet, just from memory.

[yianni]

Putting scratches on the shaft with sand paper would be difficult in such close quarters, but some permatex sealant on the edge of the o ring and flange splines might do the trick. That's what I'm planning to try this time.

[Bitsyncmaster]

Putting scratches on the shaft with sand paper would be difficult in such close quarters, but some permatex sealant on the edge of the o ring and flange splines might do the trick. That's what I'm planning to try this time.

You don't want to use permatex on any moving parts.

[PJ Grady Inc.]

I agree with the concept but not the application. OIL SEALS (the NOS DMC rear main seal for an example) often will have small diagonal ribbing near the lip edge to perform this rotational extra sealing function. Any scratches on the metal sealing area will only shred the seal in short order. In this axle flange application the oring is a stationary part on a rotating assembly and so the rotation of the part has no influence on the sealing ability.
It would be impossible to modify the oring groove areas of the spider gear without disassembling the trans and there is no reason to do so. Even then consider it's a hardened steel part with a recessed groove.
There's simply no history of leaks in this area on the DMC so the problem has to be a wrong, damaged, or incorrectly installed ORING-Period.....!
Rob


I remember a trick that was done back in the old days to get better seals on shafts. That was to put a diagonal finish on the shaft where the seal sits with some fine sand paper. That minor scratching would keep any oil from getting through the seal.

[jwrayth]

I wanted to chase this up and see if there is any special trick for installing the o-rings? My originals were leaking, replaced with DMC-EU ones and they leaked. Replaced with a X-ref of matching size... leaked. Then gave it a go with an x-ref with a wider cross-section... still leaking.

There has got to be something I'm missing here? I mean, I replaced the lip seals fine and now it's just this damn o-ring plaguing me.

[hmcelraft]

You have some old seal or other contaminate stuck on the sealing surface of the shaft inside or on the flange surface sealing the outside. I assume the seals appeared undamaged when you took them out?

[PJ Grady Inc.]

This is highly unusual as the orings almost never leak even if you don't replace them when changing the seal/axle flange. If you don't find any damage or contamination you can try an old Lotus Esprit trick and seal the splines and drift pins with hi-temp silicone sealant. This is de rigour on the Lotus setup but not usually done/required on the Delorean. I can't see why this wouldn't solve the oring issue but you may need a puller to remove them next time if there is a next time.
Rob


I wanted to chase this up and see if there is any special trick for installing the o-rings? My originals were leaking, replaced with DMC-EU ones and they leaked. Replaced with a X-ref of matching size... leaked. Then gave it a go with an x-ref with a wider cross-section... still leaking.

There has got to be something I'm missing here? I mean, I replaced the lip seals fine and now it's just this damn o-ring plaguing me.

[jwrayth]

You have some old seal or other contaminate stuck on the sealing surface of the shaft inside or on the flange surface sealing the outside. I assume the seals appeared undamaged when you took them out?

Both the lip-seals and the inner o-ring looked fine on removal. Newly placed lip seals and sleeves on the flanges are working a treat, it's just leaking down the splined shaft/down the roll pin.


This is highly unusual as the orings almost never leak even if you don't replace them when changing the seal/axle flange. If you don't find any damage or contamination you can try an old Lotus Esprit trick and seal the splines and drift pins with hi-temp silicone sealant. This is de rigour on the Lotus setup but not usually done/required on the Delorean. I can't see why this wouldn't solve the oring issue but you may need a puller to remove them next time if there is a next time.
Rob

Yeah, unusual for sure since I can't find any DeLorean threads on it other than this one! I'm going to pull the flanges again and remove the latest o-ring that I used (25mm ID, 3mm CS), clean the surfaces again and take it from there. I'll give the Lotus trick a go if it comes to it as I'm sick of this damn o-ring!

== EDIT ==
Thought I'd add for reference the o-ring I got from DMC-EU was 25mm ID, 2.5mm CS.

[jwrayth]

I have finally solved this problem and wanted to report back:

I had to put in a O-ring with 25 mm inner diameter and a 3.5 mm cross section. This appears to provide appropriate enough sealing and I am no longer leaking gearbox oil.

[Jeffu]

That's great news! Glad you got it resolved and thanks for updating the thread. :thumbup:

[OZ DMC]

I have finally solved this problem and wanted to report back:

I had to put in a O-ring with 25 mm inner diameter and a 3.5 mm cross section. This appears to provide appropriate enough sealing and I am no longer leaking gearbox oil.


I was hoping to avoid this task on 2065 but the continued leak after changing the gear box oil means this needs attention.

Just to be sure, will the DMC- OE parts fix the problem or do I need to purchase a 25mm inner diameter /3.5 mm cross section O ring to go with the seal.
Do I need any special tools for the job?

Any advice or commentary welcome.

Thank you

[jwrayth]

The DMC OE lip seal worked for me (sourced from DMC-EU), but the DMC OE o-ring did not (also from DMC-EU). With it all fitted Gearbox oil leaked along the splined shaft and out through the roll-pin. As can be seen in this thread though it appears my situation is not the normal, so the OE o-ring might suffice for yourself.

The 25mm/3.5mm cs O-ring is certainly a tighter fit and I can confirm that I've not seen the leaking re-appear after putting > 3000 miles on the car since my last updated in this thread.

[OZ DMC]

The DMC OE lip seal worked for me (sourced from DMC-EU), but the DMC OE o-ring did not (also from DMC-EU). With it all fitted Gearbox oil leaked along the splined shaft and out through the roll-pin. As can be seen in this thread though it appears my situation is not the normal, so the OE o-ring might suffice for yourself.

The 25mm/3.5mm cs O-ring is certainly a tighter fit and I can confirm that I've not seen the leaking re-appear after putting > 3000 miles on the car since my last updated in this thread.

Thank you for your response.
May I ask where you sourced the 3.5 O Ring if it was not standard and did you need any special tools for the job. The DMC manual mentions Tool J33400

Gary Cox
Australia

[jwrayth]

I purchased a bulk pack of O-rings in various sizes from a UK company Sealforce (http://www.sealforce.co.uk/), as I tested various size differences for fitment. I'm not sure of an Australian source, though you can just as easily source the specific size via places like eBay.

For removing the lip-seal and o-ring I used a small pick/hook set similar to this. You can put the new O-ring on just using your hands, though I was sure to wear fresh gloves and coat the o-ringin a little bit of fresh gear-oil first. For putting the lip-seal on I used a brass-drift and a small nylon hammer as I did not have the appropriate tool to do so otherwise. Someone else may be able to weigh in on a better tool for the lip seal :)

[OZ DMC]

I purchased a bulk pack of O-rings in various sizes from a UK company Sealforce (http://www.sealforce.co.uk/), as I tested various size differences for fitment. I'm not sure of an Australian source, though you can just as easily source the specific size via places like eBay.

For removing the lip-seal and o-ring I used a small pick/hook set similar to this. You can put the new O-ring on just using your hands, though I was sure to wear fresh gloves and coat the o-ringin a little bit of fresh gear-oil first. For putting the lip-seal on I used a brass-drift and a small nylon hammer as I did not have the appropriate tool to do so otherwise. Someone else may be able to weigh in on a better tool for the lip seal :)

I just want to check that we are talking about the same thing. I am looking to fix a leak I think is coming from the gearbox axle seals (mainly the right). I have ordered from the DMC site item 25 (2 of) part number 103013 under the heading Gearbox casing. This O ring looks approximately 75mm ID according to the scaled diagram which is considerably bigger than the 25 mm O ring you mention.

Your seal looks like the O Ring listed under Final Drive as item 1, part number 103120 which appears to have an ID of 25mm as does item 13 listed under Gears with part number 103103.

Can you confirm which O ring you replaced?

Thank you

[jwrayth]

I just want to check that we are talking about the same thing. I am looking to fix a leak I think is coming from the gearbox axle seals (mainly the right). I have ordered from the DMC site item 25 (2 of) part number 103013 under the heading Gearbox casing. This O ring looks approximately 75mm ID according to the scaled diagram which is considerably bigger than the 25 mm O ring you mention.

Your seal looks like the O Ring listed under Final Drive as item 1, part number 103120 which appears to have an ID of 25mm as does item 13 listed under Gears with part number 103103.

Can you confirm which O ring you replaced?

Thank you

It was 103120, item 1 on the "Final Drive" listing that I replaced. I did not change 103013 as I did not want to remove the diff-adjusting nut and mess with the preload on the gear-box, and I was not experiencing any leaking from around the diff-adjusting nut.

[OZ DMC]

It was 103120, item 1 on the "Final Drive" listing that I replaced. I did not change 103013 as I did not want to remove the diff-adjusting nut and mess with the preload on the gear-box, and I was not experiencing any leaking from around the diff-adjusting nut.

That is most useful. Thank you very much.

[jwrayth]

I have finally solved this problem and wanted to report back:

I had to put in a O-ring with 25 mm inner diameter and a 3.5 mm cross section. This appears to provide appropriate enough sealing and I am no longer leaking gearbox oil.

I just wanted to come back to this thread and state that as of this morning I have found gearbox oil contaminating the drive shaft boots again, which without removing the flange leads me to believe this O-ring was still not up to the task. I wish I had never tried to fix the original slight seeping of this gearbox as it's been a continued source of pain. I believe I will have to take the Lotus approach as mentioned by Rob Grady and seal the splines with silicone, though I'm sure then another leak will manifest somewhere.

[David T]

I just wanted to come back to this thread and state that as of this morning I have found gearbox oil contaminating the drive shaft boots again, which without removing the flange leads me to believe this O-ring was still not up to the task. I wish I had never tried to fix the original slight seeping of this gearbox as it's been a continued source of pain. I believe I will have to take the Lotus approach as mentioned by Rob Grady and seal the splines with silicone, though I'm sure then another leak will manifest somewhere.

With the correct "O" ring you should not have to but if you do use silicone you must also use it on the roll pin. Lotus's have a special problem with that area. If you put the flange on 180 degrees from it's "proper" position the roll pin will not go in. Deloreans don't have that problem either.

[jwrayth]

With the correct "O" ring you should not have to but if you do use silicone you must also use it on the roll pin. Lotus's have a special problem with that area. If you put the flange on 180 degrees from it's "proper" position the roll pin will not go in. Deloreans don't have that problem either.

Thanks David.

The plot thickens somewhat as when I took the drive axle off there was no sign of a leak from the splined shaft. I took the gearbox fill plug off to check how much may have leaked out, and fluid dribbled out which makes me think I haven't lost much if any fluid. The drive axle boot isn't split either, though the CV grease that escaped definitely came from the edge of the boot.

So my thinking is either;


I still have a fluid leak but only when the oil warms up
The rubber underneath the boot clamp has given way due to the previous gear-oil contamination
The CV grease got contaminated via other means (I do have a rear main seal leak and have had for some time)


I'm going to replace the boot and clean the joint either way, and was intending to get the rear main seal done again this year anyway. After that I give up and will either do the Lotus silicone approach or I'll just pay for someone else to look at it as I'm sick of it :)

[kings1527]

Thanks David.

The plot thickens somewhat as when I took the drive axle off there was no sign of a leak from the splined shaft. I took the gearbox fill plug off to check how much may have leaked out, and fluid dribbled out which makes me think I haven't lost much if any fluid. The drive axle boot isn't split either, though the CV grease that escaped definitely came from the edge of the boot.

So my thinking is either;


I still have a fluid leak but only when the oil warms up
The rubber underneath the boot clamp has given way due to the previous gear-oil contamination
The CV grease got contaminated via other means (I do have a rear main seal leak and have had for some time)


I'm going to replace the boot and clean the joint either way, and was intending to get the rear main seal done again this year anyway. After that I give up and will either do the Lotus silicone approach or I'll just pay for someone else to look at it as I'm sick of it :)

Were you able to solve this riddle? I'm dealing with a very similar situation right now (oil leak coming from the split pin hole). Thanks!

[Azar]

Same problem here :(

[DMCMW Dave]

If it's coming from the split pin you either damaged or didn't replace the rubber o-ring around the output shaft. Way down in there past the splines.

[Azar]

If it's coming from the split pin you either damaged or didn't replace the rubber o-ring around the output shaft. Way down in there past the splines.
Thanks Dave, we replaced the 2x O rings 103120. Will disassemble and check.
Can it be that the Diff Adj Nut (26) is not pushing all the way in so there is a gap inside, which the O ring can't seal?
https://www.delorean.eu/catalog/images/categorie/411.gif

[Azar]

Yes, it drops from the pin...https://uploads.tapatalk-cdn.com/20210921/5899265456b3312e8917dafa9976b7b6.jpg

[DMCMW Dave]

If the roll pin is installed, the flange is in all the way. May have chipped or split the O-ring. Be sure to oil it when installing.

[Azar]

The DMC OE lip seal worked for me (sourced from DMC-EU), but the DMC OE o-ring did not (also from DMC-EU). With it all fitted Gearbox oil leaked along the splined shaft and out through the roll-pin. As can be seen in this thread though it appears my situation is not the normal, so the OE o-ring might suffice for yourself.

The 25mm/3.5mm cs O-ring is certainly a tighter fit and I can confirm that I've not seen the leaking re-appear after putting > 3000 miles on the car since my last updated in this thread.And yes, I got the DMC-EU lip seals and O-Rings.... Just ordered 3,5 mm thick ones....

[Azar]

If the roll pin is installed, the flange is in all the way. May have chipped or split the O-ring. Be sure to oil it when installing.Thanks Dave, will do. I hope it is an easy job, just need to unscrew the drive shaft bolts...

[DMCMW Dave]

Thanks Dave, will do. I hope it is an easy job, just need to unscrew the drive shaft bolts...

Biggest thing - be careful which direction the pin is going when you drive it back out. It's really annoying when you punch it out of the flange and into the side of the case, and then can't rotate the flange to keep it going or get it back in.

Then pull the flange off, and reach in with a pick tool to remove the o-ring. If the o-ring has split it may fall into the trans, so go slowly.

[Helirich]

I remember a trick that was done back in the old days to get better seals on shafts. That was to put a diagonal finish on the shaft where the seal sits with some fine sand paper. That minor scratching would keep any oil from getting through the seal.

I've seen that also. You have to take in account the direction of rotation or you will be pumping the oil past the seal.

[Azar]

Biggest thing - be careful which direction the pin is going when you drive it back out. It's really annoying when you punch it out of the flange and into the side of the case, and then can't rotate the flange to keep it going or get it back in.

Then pull the flange off, and reach in with a pick tool to remove the o-ring. If the o-ring has split it may fall into the trans, so go slowly.

Thanks Dave, did as you instructed. The 3,5mm thick O-Ring which I retrieved had some old white silicone on it. So I have installed new 3,5mm thick O-Ring and put black silicone on it. No leak for 10 days so far!

[82DMC12]

Thanks Dave, did as you instructed. The 3,5mm thick O-Ring which I retrieved had some old white silicone on it. So I have installed new 3,5mm thick O-Ring and put black silicone on it. No leak for 10 days so far!

I have my axles and flanges out right now myself. Where did you put the black silicone? I'm confused.

[Azar]

I have my axles and flanges out right now myself. Where did you put the black silicone? I'm confused.I am sorry, looks like I missed your question...
I just put silikon on the inner O ring and pushed the Flange in.