Kiln_Red

Yes, and in that order. Coat the threads with blue Loctite and torque the rear bolt first.

Dave928S

Here's a full run down in detail, from start to finish, which follows the previous brief list, but expands on all the detail.

Manual transmission pinch bolt replacement.

1. Remove the access plug which allows you to get to the single rear pinch bolt, fitted to the clamp, which is a slide fit on the gearbox input shaft. Note that this clamp is not fixed to the input shaft, and can be dragged forward a little by the bolt in it, which is being pulled forward by the main drive shaft.

2. Transmission in neutral and clutch depressed, will allow you to rotate the shaft to see/access the bolt head on the rear clamp. Depress the clutch pedal fully to disengage the TT from the motor, and have someone else hold it there, or held there using a piece of wood from the front of the seat frame. With the clutch pedal depressed and the gearbox in neutral it will allow you to turn the shaft either way, to line it up with the inspection opening without having to turn the motor or wheels, and will allow you to rotate it easily after you've removed the bolt to have a good look at everything.

3. Once you have the bolt lined up you can release the clutch pedal to hold the bolt head in that rotational position to make it easier to undo … and to torque the new bolt later.

4. As noted in #1 above, the shaft may have moved forward, and when it does it drags the bolt and clamp with it, relative to the gearbox input shaft. If this has occurred, the bolt head will be towards the front of the access opening, and may be difficult/impossible to get out.

5. To lever the shaft back to its original position, along with the rear bolt and clamp, you next need to remove the lower bellhousing so that you can lever the shaft back.

6. To remove the lower bellhousing, remove the clutch slave cylinder after detaching the hard line clamp to allow its detachment. To avoid fluid loss, do not detach the hydraulic line, and make sure the clutch pedal cannot be mistakenly depressed, by tying the pedal to the steering wheel. This will disable your ability to turn the shaft freely, without turning the motor, so ensure the rear bolt is still lined up. Remove the six bolts holding the cover on, and remove the cover.

7. Do not loosen or remove the two bolts on that front clamp until you have the rear lined up, inspected, and the new bolt torqued in place. Using a jemmy bar, apply rearward force on the front clamp (which is still bolted to the shaft at this stage), to force the shaft back in the TT a little, to line the shaft up at the rear. When you force the shaft back it will allow the bolt and clamp to move back also (might need a bit of a lever with a screwdriver), which will mean the clamp and bolt will be closer to central of the inspection opening, and the bolt will now come out easily without the shaft pressing forward on it.

8. Remove the old bolt and have a good look at it for damage, indicative of it being rammed against the groove/spline edge.

9. Prise the clamp on the gearbox input shaft forward, so it is no longer on the input shaft, which will allow you to inspect that for fatigue cracking at the base of the splits in the hollow shaft. To inspect it carefully you will need to rotate the shaft by turning the motor. Look also for a lot of red dust, which can be present from spline wear. Once you are satisfied that there is no problem, you can slide the clamp back on (retrieve with a magnet or grab tool if necessary), make sure the main shaft groove is in line with the bolt recess in the input shaft, fit the new bolt, and torque to 66 ft/lbs. Note: I don’t apply Loctite, because I believe it will give a false sense of security … that is, checking later, the bolt could be stretched and not providing adequate clamping, but the torque reading with Loctite hampering rotation might read OK.

10. Now that the rear is complete, and in the correct position, you can work on the front clamp and two bolts.

11. Remove the front two clamp pinch bolts and then ensure that the stub and main shaft grooves are correctly aligned, and that the stub shaft is adequately engaged in the crank pilot. This needs to be checked, because the forward push of the main shaft may have closed the gap between the two shafts, and both bolts may have been at the extremities of the shaft grooves, and not centred. Once alignment is correct, fit two new bolts and torque to 66 ft/lbs. Again .. I don’t apply Loctite, to allow subsequent accurate re-torqueing.

12. Before re-fitting bell housing you have the opportunity to inspect and adjust the clutch.

13. Refit lower bell housing and clutch slave.

bureau13

Do all 3 (?) of the pinch bolts get the same increased torque applied as the rear?

Dave928S

Yes ... the one at the rear and the two at the front are all torqued to 66 ft/lbs.

SMTCapeCod

Seems like one series indicates removal of front bolt first, to allow for freeing up the rear bolt from any contact/compression, and the other set of steps does rear first, then front.

Dave928S

A manual cars front stub shaft is floating and will freely allow the main shaft, to which it is connected, to slide back (unless it's welded into the pilot bearing). Leaving those bolts tight also allows you to pry the main shaft rearwards, by levering the clamp back. My abbreviated list, and expanded version above, are the same.

Slightly different procedure for an auto, where the flexplate would/could restrict rear travel.

ltoolio

Just got a bit of time under the car, and with the exhaust till on, the lower bellhouse removal looks to be very tight given the limited clearance. This appears to be the case even when I remove the starter and the clutch slave.

But...while I was down there, I found an observation hole on the front of the TT, which lets me see the front clamp. Can I just apply pressure to the clamp, using the observation hole as a fulcrum, to push the shaft back?

I'll go the full bellhouse route, but damn does that look tight and I have some concerns about my ability to get things back together given limited space.

Dave928S

You could just lever it back from there, but it would be a better result if you can also do the front, which allows you to adjust the two bolts with the stub and main shaft grooves, and will give correct stub shaft engagement with the pilot bearing.

If you can get the lower bellhousing off, no matter how tight the clearance ... then there's no reason you shouldn't be able to get it back on again.

You'll never know if you don't give it a go

ltoolio

Thanks, Dave. I needed a bit of confidence to go through with doing it the right way, and that's precisely what you gave me

Wisconsin Joe

My experience with my 85 (stock exhaust) was that there is just enough room to get it out & back in.

ltoolio

I've dove in feet first and things are moving along (thanks again for the nudge of confidence)

I have hit one snag, though -

I can't get to the top bolt of the starter. A 17mm open wrench doesn't fit between the starter and the headers. I can't get to it from above on the PS, nor can I get to it from between the starter and the OP.

I *might* be able to get it with a 17mm socket and get some small movement, but the hard line for the clutch slave blocks that access, and I can't shift it enough.

**Edit** - overthinking this a bit. 17mm socket with some extensions so I can get the wrench in front of the starter should work. Back to work I go.

Dave928S

Keep up the good work and keep posting updates! You'll get there.

When it comes to levering the shaft back you might be wondering exactly how much you'll need to move it. The answer is that it depends on how far it has progressed through the following chain of events. As it's off center and difficult to get out ... probably all three.

1. The shaft has moved forward (from the shaft groove being centred to the bolt), until the rear of the shaft groove has hit the bolt.

2. The shaft has pulled the bolt and the clamp (which can move on the gearbox input shaft) further forward, until it is against the front of the input shaft groove.

3. The shaft may have continued to pull forward and the bolt has worn into the groove/spline edge.

My '82 had moved forward about 5.5 - 6 mm, with about 2 mm of that being wear into the shaft spline edge (step #3).

So ... I think you can count on at least 4 mm, and maybe a fraction more.

A final check, when you've finished the back and working on the front, will be that the front end of the main shaft should be projecting about 2 mm further forward than the front TT flange face.

Wisconsin Joe

#1 - The hardline for the clutch is attached to the oil pan with a little bracket. Undo that and you get more room (when I did my pan gasket, I went with the stud kit. I deliberately left that particular stud out a bit so that I could use an extra nut to attach the clutch line - that way I don't have to loosen the pan itself to pull the line off).

#2 - Do you have actual hex bolts on your starter? I have allen bolts. The top one is a pain in the (insert favorite body part here) to get at. I use a ball end wrench once it's loosened.

ltoolio

Just got back from under the car, and I remained stymied.

I have undone the hardline bracket and yes...it give me some room, but not enough.

The bolts for the starter are in fact Hex, not Allen. I can get a socket on the bolt, but the extensions hit up against the hard line, which hits up against the OP, which prevents me from being able to get the extension into the socket.

I tried a Crows Foot, but it's too fat to fit around the bolt - it bumps up against the OP and the starter.

I also tried a standard wrench again, and the headers prevent me from getting any sort of grip on the bolt.

I thought about trying to release the bellhouse with the starter still on, hoping to get some additional clearance, but that seems fraught with all sorts of potential things going wrong.

So...totally stumped at the moment. I'm thinking about getting a stubby 17mm wrench and maybe even cutting it down further so I can avoid the headers, but that too seems like it might force things to go bad (most notably banging into the hard line and f'ing that up).

ltoolio

3/8" 17mm Socket -> 3/8" to 1/4" Adapter -> 1/4" extension -> 1/4" to 3/8" adapter -> 3/8" wrench gives me what I need. The 1st adapter and the 1/4" extension are slim enough to let the hard line float between the extension and the OP.

Bolt is pretty well stuck. Got some PB on it, so hopefully off later