Rear torque tube pinch bolt
10-21-2002, 09:49 PM
#1
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Rear torque tube pinch bolt
My rear torque tube pinch bolt is coming loose now for the fifth time. Which makes for a nice rattle when turning off the car. Since I thought I am doing something wrong torquing it down, I took it to the shop today and had it looked at. They initially tried to torque it with 58 pounds and it didn't move. The owner seems very knowlegebale and pointed out to me that there is something wrong with the "clamp" (I'm not sure how to call it) at the rear end of the shaft. When turning it over slowly, it almost looks like a peace broke off at the front of the "clamp". Does anyone have some pictures how it is supposed to look? I would hate having them drop the tranny just to find out that's the way it's supposed to be.
Thanks,
Sab. <img src="confused.gif" border="0">
Thanks,
Sab. <img src="confused.gif" border="0">
10-21-2002, 11:19 PM
#2
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Hi Sab,
Tony comes through again... I think. See if some of these pictures help.
<a href="http://members.rennlist.com/v1uhoh/torque.htm" target="_blank">http://members.rennlist.com/v1uhoh/torque.htm</a>
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
Tony comes through again... I think. See if some of these pictures help.
<a href="http://members.rennlist.com/v1uhoh/torque.htm" target="_blank">http://members.rennlist.com/v1uhoh/torque.htm</a>
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
10-22-2002, 09:12 AM
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Thanks Thom,
yes one of the pictures looks just like it, but it seems to be the front clamp. Mine looks just like it but the piece I highlighted in the picture seems missing or broken off.
regards,
Sab.
yes one of the pictures looks just like it, but it seems to be the front clamp. Mine looks just like it but the piece I highlighted in the picture seems missing or broken off.
regards,
Sab.
10-22-2002, 02:02 PM
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Hi Sab,
Sorry but that looks like the pinchee, not the pincher, that is broken off. The pinch collar is to the right. The bolt head in the collar is about the same width as the rest of the collar. The pinch collar is similar to an exhaust manifold clamp.
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
Sorry but that looks like the pinchee, not the pincher, that is broken off. The pinch collar is to the right. The bolt head in the collar is about the same width as the rest of the collar. The pinch collar is similar to an exhaust manifold clamp.
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
10-22-2002, 05:05 PM
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Sab - just done my torque tube (last weekend).
The collar at the back end is a square section clamp with a small cut in one side which allows the pinch bolt to tighten the clamp down onto the pinch collar - the pinch collar is a splined shaft (on the inside) and semi tapered on the outside which extends forwards from the torque convertor flex plate (which bolts to the torque convertor). This stub shaft passes through a carrier bearing on the inner side of the torque convertor housing, a spacer bush and then another bearing in the outer side of the torque convertor housing. The pinch bolt itself passes through a cut out in the side of the stub shaft and into a recessed face of the shaft thus locking the shaft and preventing fore and aft movement - all movement under torque is damped by the flex plates at this and the front end.
If this section is broken out - a) where did the broken bit go(!) and b) the chances are your stub shaft now has more than a cut out and the pinch bolt is not capable of sitting in the cut out correctly under torque - thus the constant loosening.
Remedy......back end out I am afraid followed by a new rear flex plate. If you enlarged the inspection hole in the tube (and were a clever welder) you could spot weld the closed side of the clamp to the stub shaft.....(the front flex plate clamp is spot welded)....... if the clamp cannot move then the bolt should still sit in the recess on the shaft unless the movement allowed in the past has worn this section also?
The best option is to get in there and change the bit, you might want to do the tube whilst there as well as the torque convertor bearings .......... mine had started to destroy themselves!
The job took me 14 hours start to finish and is not as difficult as it sounds or reads up. In a shop with a lift I managed to drop the rear suspension / transaxle complete (only removing the calipers) and without possibly affecting the suspension alignment settings.
If you want to contact me off list for a total run through the job please do so.
Good luck!
Andy
The collar at the back end is a square section clamp with a small cut in one side which allows the pinch bolt to tighten the clamp down onto the pinch collar - the pinch collar is a splined shaft (on the inside) and semi tapered on the outside which extends forwards from the torque convertor flex plate (which bolts to the torque convertor). This stub shaft passes through a carrier bearing on the inner side of the torque convertor housing, a spacer bush and then another bearing in the outer side of the torque convertor housing. The pinch bolt itself passes through a cut out in the side of the stub shaft and into a recessed face of the shaft thus locking the shaft and preventing fore and aft movement - all movement under torque is damped by the flex plates at this and the front end.
If this section is broken out - a) where did the broken bit go(!) and b) the chances are your stub shaft now has more than a cut out and the pinch bolt is not capable of sitting in the cut out correctly under torque - thus the constant loosening.
Remedy......back end out I am afraid followed by a new rear flex plate. If you enlarged the inspection hole in the tube (and were a clever welder) you could spot weld the closed side of the clamp to the stub shaft.....(the front flex plate clamp is spot welded)....... if the clamp cannot move then the bolt should still sit in the recess on the shaft unless the movement allowed in the past has worn this section also?
The best option is to get in there and change the bit, you might want to do the tube whilst there as well as the torque convertor bearings .......... mine had started to destroy themselves!
The job took me 14 hours start to finish and is not as difficult as it sounds or reads up. In a shop with a lift I managed to drop the rear suspension / transaxle complete (only removing the calipers) and without possibly affecting the suspension alignment settings.
If you want to contact me off list for a total run through the job please do so.
Good luck!
Andy
10-23-2002, 09:43 AM
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Thanks Thom, thanks Andy,
so it looks like one of the three sections of my pinch collar is broken off. Looking through my receipts from the PO I saw that he had the torque tube replaced by the dealer for around $2,000 in 1999. I suspect they probably broke the pinch collar reinstalling it.
Looks like I am in for a major expense. I don't have access to a lift, so I guess I'll have it done. What should I expect to be charged?
Is that whole rear flexplate and pinch collar one piece?
My tranny has a leak aparently on the front seal, so it might just be a good time.
If I have it all taken apart, what else should be done or looked at at that time?
Thanks and regards,
Sab. <img src="graemlins/c.gif" border="0" alt="[ouch]" />
so it looks like one of the three sections of my pinch collar is broken off. Looking through my receipts from the PO I saw that he had the torque tube replaced by the dealer for around $2,000 in 1999. I suspect they probably broke the pinch collar reinstalling it.
Looks like I am in for a major expense. I don't have access to a lift, so I guess I'll have it done. What should I expect to be charged?
Is that whole rear flexplate and pinch collar one piece?
My tranny has a leak aparently on the front seal, so it might just be a good time.
If I have it all taken apart, what else should be done or looked at at that time?
Thanks and regards,
Sab. <img src="graemlins/c.gif" border="0" alt="[ouch]" />
10-23-2002, 03:58 PM
#7
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Hi Sab,
Looks like Andy can help more with the technical aspects of that job. I looked at PET, and found that Tony and I do not use “Pinch Collar” the same as Porsche. They call that a clamping piece. For the 1986 automatic model, the thing we call a “flex plate” is a carrier plate. PET does not provide a parts breakdown of the carrier plate that I can find. Maybe Andy can verify that the carrier plate is broken.
I would try some Valvoline MaxLife Automatic Transmission Stop Leak in the concentrate before I messed with the torque converter and oil pump seals. My Porsche certified mechanic has had my car for 2 months now trying to seal that area. I just found out that we have been waiting for a housing from Stuttgart for the last 3 weeks. He replaced all the seals in that area 3 times, and it leaked more than it ever did before the service each time. It appears now that there is a hairline crack in that housing. The darn thing did not leak enough to top it off but once every year or two before I took it in. The stop leak has worked for one of our consulting experts. I thought I could permanently fix the nuisance leak while I was replacing the torque tube, and torque converter bearings. It is driving me crazy to spend 2 or 3 months on a 3 or 4 day job.
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
Looks like Andy can help more with the technical aspects of that job. I looked at PET, and found that Tony and I do not use “Pinch Collar” the same as Porsche. They call that a clamping piece. For the 1986 automatic model, the thing we call a “flex plate” is a carrier plate. PET does not provide a parts breakdown of the carrier plate that I can find. Maybe Andy can verify that the carrier plate is broken.
I would try some Valvoline MaxLife Automatic Transmission Stop Leak in the concentrate before I messed with the torque converter and oil pump seals. My Porsche certified mechanic has had my car for 2 months now trying to seal that area. I just found out that we have been waiting for a housing from Stuttgart for the last 3 weeks. He replaced all the seals in that area 3 times, and it leaked more than it ever did before the service each time. It appears now that there is a hairline crack in that housing. The darn thing did not leak enough to top it off but once every year or two before I took it in. The stop leak has worked for one of our consulting experts. I thought I could permanently fix the nuisance leak while I was replacing the torque tube, and torque converter bearings. It is driving me crazy to spend 2 or 3 months on a 3 or 4 day job.
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
