Weird sound in 5th gear...

[rothsean]

So it happened 3 times in the past 2 months where I am driving down the road 55mph+n 5th gear and all of a sudden I hear a slightl grinding noise. The first time I thought that I had ran over a cardboard box and was dragging it. Anyways, ends up being if I shift to neutral then back into 5th gear the sound goes away.

Any ideas?

[vwdmc16]

Your trans is popping out of gear, I have the same issue however it has progressed much worse, I have been keeping track of how many times the trans has fallen out of 5th gear, Im at 22 times in the last 4 months now. Usually it happened when decelerating lightly but it can occur on level ground while cruising. The problem can be a few things like slop in the shift linkage or somthing blocking it, in my case the issue is the 5th gear Detent is not holding the 5th gear shift shaft in place enough, this is because the ball bearing that is the detent is not moving freely enough due to either dirt of most likely dried up grease that lubricates it and the spring. The detent is located in the nose cone of the trans behind a large flat head screw cap, you can see it on the passenger front end of the trans nose cone. The detent can be removed and cleaned and lubricated in the car if you can remove the flat headed screw cover, I was unable to do this on my car due to all the corrosion the underside has succumb to.


You need to look into repairing this sooner than later, My issue has gotten worse over the last 6 months and any time you have a gear that is partially engaged, you can damage the teeth and syncros, making the repair even more troublesome and expensive.

[rothsean]

OK, cool, I will check into this.

Thanks!

[David T]

I agree it should be attended to sooner rather than later. It could be you are low on oil or don't have the right kind. It could also be the nut on the end of the shaft is loosening. You can pull the front end cover off of the transmission with it in the car, just drain the oil out first. Check all of the external simple stuff first like the linkage for looseness and adjustment.
David Teitelbaum

[rothsean]

Your trans is popping out of gear, I have the same issue however it has progressed much worse, I have been keeping track of how many times the trans has fallen out of 5th gear, Im at 22 times in the last 4 months now. Usually it happened when decelerating lightly but it can occur on level ground while cruising. The problem can be a few things like slop in the shift linkage or somthing blocking it, in my case the issue is the 5th gear Detent is not holding the 5th gear shift shaft in place enough, this is because the ball bearing that is the detent is not moving freely enough due to either dirt of most likely dried up grease that lubricates it and the spring. The detent is located in the nose cone of the trans behind a large flat head screw cap, you can see it on the passenger front end of the trans nose cone. The detent can be removed and cleaned and lubricated in the car if you can remove the flat headed screw cover, I was unable to do this on my car due to all the corrosion the underside has succumb to.


You need to look into repairing this sooner than later, My issue has gotten worse over the last 6 months and any time you have a gear that is partially engaged, you can damage the teeth and syncros, making the repair even more troublesome and expensive.


How did you diagnose yours? So I just remove the nose cone cap and spray grease in there?

[Nicholas R]

In this blog post I documented my disassembly of the transmission. It talks about both the 5th gear detent and the removal of the rear cone. May give you some insight as to what all you'll be looking at and looking for:
http://ls1delorean.blogspot.com/2011/10/i-wonder-whats-inside-transmission.html

Also this was the post about reassembling the transmission. May also have some good info and photos:
http://ls1delorean.blogspot.com/2012/02/time-to-rebuild.html

[vwdmc16]

Right pictures make a huge difference. Like i said if you can get the cap over the detent out then there is no need to pull the nose cone off which is a lot more work. First however, check simpler things like the oil level and state and look for any linkage binding.

[Nicholas R]

http://1.bp.blogspot.com/-iuxtFBUBobA/To9uUNwlajI/AAAAAAAAAD0/hYVI35HxNb4/s1600/DSC_0227+%255B1600x1200%255D.JPG

For reference, this is the screw holding the detent in place. When you remove it, there will be a spring and a ball bearing underneath. Remove it slowly as the spring is under pressure. You may need a small magnet if you want to remove the ball bearing.

[rothsean]

http://1.bp.blogspot.com/-iuxtFBUBobA/To9uUNwlajI/AAAAAAAAAD0/hYVI35HxNb4/s1600/DSC_0227+%255B1600x1200%255D.JPG

For reference, this is the screw holding the detent in place. When you remove it, there will be a spring and a ball bearing underneath. Remove it slowly as the spring is under pressure. You may need a small magnet if you want to remove the ball bearing.


So you just remove the screw and bearing, take it out and clean it, then grease it, then re-install?

[vwdmc16]

Thats right, clean the bore with a pipe brush and try to get old dry grease out. Clean the spring and ball that you will need a magnet to remove. Grease with something like axle grease and drops of trans oil. Now this all sounds easier than it will be, and it only the likely problem, this s may not cure all.

[DCUK Martin]

I wouldn't go greasing it at all - it's meant to be lubricated by the transmission oil and mixing lubricants, expecially grease in oil, is exactly the sort of thing that can gum things up.

[Nicholas R]

I wouldn't go greasing it at all - it's meant to be lubricated by the transmission oil and mixing lubricants, expecially grease in oil, is exactly the sort of thing that can gum things up.

Agreed, I would just clean it really well; ball, spring, screw, and the hole they live in. Clean any gunk off you can.

[David T]

It should all be clean, if not just clean it up. It can't hurt to use some light oil when you reassemble. Make sure the spring is not bent. Doubtful that it is the problem but it can't hurt to check.
David Teitelbaum