Shift linkage pivot bolt

[82DMC12]

Well I'm currently sitting here waiting for a flatbed tow truck to get my car home because I believe my linkage pivot bolt has sheared off. This is part number 17 on the manual transmission linkage diagram. This happened to me once before about 20 years ago. My transmission shifts very nicely so it's not like I have to jam it into gear or anything.

My shifter is just flopping around and I'm stuck in neutral.

Is this just a really common problem or is there something else I should be looking at to figure out why this has happened to me twice now?

I'm buying two pivot bolts this time.

Once I get home I'll get underneath and confirm.

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[82DMC12]

Sure enough, pivot bolt is the problem, but it didn't break off. It somehow unscrewed itself from the frame. Looks like I need a new jamb nut (missing) and I'll use blue loctite this time.

How do I know when the bolt is tight enough? Seems like I can make it so tight that the arms will bind?

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[82DMC12]

Oh - and thank God the threads in the frame are fine! This will be an easy fix, really only for the price of the tow. And all I wanted to do tonight was watch the Chiefs game!

And fortunately the tow driver has towed DeLoreans before :-)

[Bitsyncmaster]

The bolt should seat on the frame and therefor should be torqued tight. Mine the epoxy on the frame in that area was all gone and it had a lot of rust. I machined my pivot arm with a new bearing and seat for the bearing so I just use a standard bolt. Probably something DPI should produce and sell.

The third photo is the stock bolt. So it looks like you can grind or file some of the pivot arm so your bolt will not bind.

[82DMC12]

Dave, thanks.

I'm confused though. In the fourth picture, what is all that? An O-ring? And a stainless bush? I don't think I have any of that. I just have the bolt I posted above with a single thin washer, which is what that parts book is also showing.

I just got a new jamb nut at the hardware store. I'm going to put this back together good enough so I can get to my alignment appointment on Tuesday, but I will do a thorough job of replacing the bad bushings on the ends of the bellcrank ASAP.

PLUS - looking at your picture - seems like my bolt doesn't have long enough threads. I remember I got this from Hervey way back in the day, he was kind enough to overnight it to me when my car was broken down at a shop for the exact same thing. Maybe this bolt isn't the right thing at all.

Going to order all new everything tomorrow I guess.

[82DMC12]

I put the pivot bolt and washer back in just to get the car mobile. Interesting to note that the Parts Manual I have (Grady physical copy) shows the washer directly under the bolt head (above the bellcrank) with NO washer between the bellcrank and frame.

delorean.com shows the washer UNDER the bellcrank with no washer under the bolt head.

Which is "correct"? I see delorean.com has a superseded part for the pivot bolt so is the new design/part reflecting in the revised diagram online? I will check with DMCMW tomorrow.

I really do not like this bolt I have because the jamb nut I bought tonight barely threads completely onto the bolt. This bolt must be too short. I have to tighten the jamb nut fairly tight to keep the bellcrank from turning the pivot bolt right out of the frame again. WTF?

[Bitsyncmaster]

Dave, thanks.

I'm confused though. In the fourth picture, what is all that? An O-ring? And a stainless bush? I don't think I have any of that. I just have the bolt I posted above with a single thin washer, which is what that parts book is also showing.

I just got a new jamb nut at the hardware store. I'm going to put this back together good enough so I can get to my alignment appointment on Tuesday, but I will do a thorough job of replacing the bad bushings on the ends of the bellcrank ASAP.

PLUS - looking at your picture - seems like my bolt doesn't have long enough threads. I remember I got this from Hervey way back in the day, he was kind enough to overnight it to me when my car was broken down at a shop for the exact same thing. Maybe this bolt isn't the right thing at all.

Going to order all new everything tomorrow I guess.

Mine is modified. That last photo is a new part I machined which gets bolted tight onto the frame. I needed a larger surface area where it contacts the frame because of the damaged epoxy. So the new bearing (not stock) uses that new machined part (not stock) to rotate around. That gives me a design so the bolt has very little lateral force so the bolt just holds it onto the frame.

The OEM design the bolt is the surface of the rotating part of the bell crank. So the bolt must be tight since it is the pivot with all the lateral force on it.

[DMC-81]

I replaced mine in 2018 with a new bellcrank assembly (100549) from DMC and an improved grade 12.9 Shift Pivot Bolt & Hardware from PJ Grady.

Here is how I put it together:


I lubed the assembly with a 50/50 mixture of anti-sieze and axle grease, and applied red loctite to the jam nut:

[82DMC12]

I replaced mine in 2018 with a new bellcrank assembly (100549) from DMC and an improved grade 12.9 Shift Pivot Bolt & Hardware from PJ Grady.

Here is how I put it together:


I lubed the assembly with a 50/50 mixture of anti-sieze and axle grease, and applied red loctite to the jam nut:

Excellent, thanks! I have all new hardware and bushings for the rods coming tomorrow.

Andy

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[DMC-81]

Excellent, thanks! I have all new hardware and bushings for the rods coming tomorrow.

Andy

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You are welcome. Here are the details when I replaced the part as posted in my transmission rebuild thread:

http://dmctalk.org/showthread.php?14...l=1#post232838

and here is the service bulletin with more details and torque specs:


As I recall regarding the sequence of the washers, the thick washer goes on top of the bellcrank as pictured, but the 2 wavy washers go on the bottom between the bellcrank and the frame, leaving no washer between the jam nut and the frame. I would test the arrangement out for proper movement before using loctite in the final assembly.