Rear oil seal et al

[foster461]

One more data point, snipped from  http://www.mntriumphs.org/Tech_Info/Clutch%20Folder/clutch.pdf

 

 

Update – October 2003

 

Thanks to Mr. Thomas Fremont, another mechanical engineer; University of Cincinnati, 1987; there is

another theory to the sticking clutch problem. Tom’s theory is that the misalignment between the engine and

transmission causes the sticking clutch. He solves the problem by using two 21/64” drill bits as temporary

dowels to align the transmission to the engine. His theory is backed-up by the fact that all but four bolts

holding the transmission to the engine are 5/16” diameter. Four bolts are 3/8”. Two of the 3/8” bolts hold

the starter on and the other two are at about the 4:00 and 10:00 positions. These two 3/8” bolts fit tightly

and are often not reinstalled because they won’t fit.

Could it be all of the clutch problems are because of two lousy 3/8” bolts and can be solved by two 21/64”

drills? Maybe. This theory would explain Mr. Nelson Riedel‘s theory of the dragging release sleeve on the

transmission input housing and maybe the excess drag between the sleeve and housing causes a stiff clutch.

[foster461]

And one more from John at TRF..

 

Thanks for writing.  Originally there were two dowel bolts used along with regular bolts to center the gearbox in relation to the clutch and engine.  Over the years, I would expect that these bolts have disappeared as people reinstalled gearboxes with whatever they had at hand, not realizing that the dowel bolts were necessary or even there.  The dowel bolts were part number 132872 and they are no longer available.

 

 

The man who supplies the Gunst throwout bearings is a firm believer that the dowel bolts are necessary for proper clutch operation and he blames the absence of the bolts for some of the problems associated with the clutch hanging up on the front cover of the gearbox.  Because the bolts are not available, he supplies dowel pins with his throwout bearing kit that he actually buys from us.  Our part numbers for the pins is DP612, price is $0.99 each.  We have good stocks on hand.  To order, please call us at 800 234-1104.  You might want to include these with others parts as shipping would be $6.95 for parts orders up to $20.00.

[foster461]

The new seal is in, not a bad job really. The old seal was definately leaking, either because it was not centered correctly on the crank (the book says to rotate the crank a few times with the seal housing bolts just finger tight to center the seal) or maybe because a rough spot I noticed on the crank surface that the seal interfaces with. My only problem was that the sump gasket was well and truly stuck to everying with some hard setting compound and the area of the gasket that was under the rear oil seal housing in now toast so I'm going to have to remove the oil pan once I get the gearbox re-attached, chip off the rest of the gasket and fit a new one. Not a big deal. I can check the thrust washers while I have the bottom end exposed..

 

I fitted a new spigot bearing and replaced the old borg and beck clutch with a Sachs unit in the hope that the clutch will engage with less than super human effort.

 

I'm picking up my gearbox tomorrow with the newly added overdrive and John Esposito who did the rebuild tells me that the reverse idle and 1st and 2nd synchro hub had to be replaced because it looks like the clutch was not fully disengaging. Not sure what is going on there but I did refurb the master and slave cylinders while I was waiting for the gearbox to come home and I'll pay special attention to the clutch engagement when I put it back together.

 

I am really looking forward to the overdrive..

 

Stan

[foster461]

Well, I'm having no luck getting the gearbox back in.. There must be a trick to this because all the things that need to be in alignment are inside the bell housing where you cant see them.. It looks like it should just slide in but it stops short with just over an inch to go. The release bearing is not interfering and I checked that the input shaft fits into the new spigot bush in the flywheel so it must be an alignment thing.

 

Any words of wisdom ?. This gearbox now has overdrive, do I need to remove the rear mounting bracket to allow more wiggle room ?

 

Stan

[Richard Crawley]

Stan.

You are spot on with the 2 dowel bolts; these are vital & many go missing over the years. Mine are still there, I’ve had the car since 35K & believe I was the first to take it out!

 

It certainly sounds like you are getting a problem on that last little bit when trying to engage with the spigot bearing. You do have to be quite brutal (within reason) sometimes especially if a new bearing has been fitted. On my last attempt, I fought with mine for about 5 minutes before a final energetic flurry & rotating the box slightly slammed it all home.

[chrismitchell]

At Malvern last year I got a plastic alignment tool which is perfect fit for TR6 clutch, works very well, gearbox slipped straight in. Only a couple of quid, I think it was TR Shop (chiswick) but not absolutely sure.

[jonlar]

May be a silly question Stan, but have you checked the friction plate splines slide easily over the input shaft splines (with some grease - otherwise you can end up with a sticky change - and unable to get reverse with engine and parts hot)?   Leave box in reverse or a forward gear and rotate prop-shaft flange as you push G/B unit to the engine, this'll rotate input shaft and hopefully pick up the splines (apologies, if this is Granny and sucking eggs!!).

[Richard Crawley]

Sorry Jonlar but on no account would I use grease on the splines or any other part of the clutch for that matter; this could contaminate the clutch plate causing judder & dust wearing from the friction plate will stick to it like the proverbial to a blanket & you will end up with a clogged up mess. I always use silicone spray on the spines at initial assembly but make sure you keep this well away from the clutch assembly.

[Guest ron]

Err, I've lightly greased numerous clutch splines over the last 30 years and never had any bother, usually use copper slip, I think if a bit of common sense is used about the quantity you shouldn't have any problem.

The other mod that improves a TR6 clutch is a phosphor/bronze bearing carrier rather than a steel one, it's less likely to bind on the gearbox nose spiggot and it doesn't have the two pins so it is free to rotate, spreading the wear instead of concentrating it at two points.

Ron

[jonlar]

Richard, like Ron I've always assembled clutches with splines "lightly" greased (usually Castrol Moly)and never had a problem.   The one occasion I assembled one dry, after 3 or 4 months, I had to turn engine off and engage reverse, then restart.    I've found that silcone spray and WD40 dry out very quickly.   Any excess grease tends to get squeezed off the splines and back onto the release bearing where it gets thrown off.

[foster461]

An aligment tool came with the clutch kit and I used the new clutch plate to spread the light film of lithium grease I used on the splines so I know that fits. Also I am in far enough that the rear flange will no longer rotate with the gearbox in gear so I think I have entered the plate at this point. It is a new spigot bush and it was a fairly tight fit athough easily placed and removed on the end of the input shaft. I think my biggest problem is that the gearbox with OD weights around 90 lbs and one guy alone is going to have a hard time getting things lined up and applying enough leverage to shove the thing home.

 

What about the rear bracket ? the bracket does limit how low the rear of the unit can go. Since this is a new OD I have no explerience with this configuration.. do people normally just leave the rear bracket in situ and find the box goes in with no problem ?

 

Stan

[jonlar]

Stan, have you tried raising/lowering the rear of the engine slightly to get a small change in the "angle of attack"?

[Tom Fremont]

Just weighed one at 97 lbs drained - a load indeed for a 150 lb mechanic of 50 years lke me, or anyone else perhaps....Seems to always be a wrestling match to refit them!

 

Thanks the references to my previous advice about using drill bits for temporary dowels - I think the correct size is 11/32" rather than 21/64", which would be loose.

 

Richard's possession of the original dowels is the only case known to me so far - I suspect their absence is principally what spawned a cottage industry in substitute hardware for the clutch throwout mechanism! ::

[Barry]

Stan, The bracket stays where it is,I use a large crowbar between the flanges,I know it seems brutal but it works for me.It is better if you can get someone to wiggle the box while you lever it.

Good luck.

Barry.

[Guest ron]

Stan

The last time I fitted the gearbox it took two of us [both slightly past the first bloom of youth!], I think it would be a bit of a struggle to manage it yourself. If I remember right I had to do a fair bit of adjusting of the rear height of the engine with a jack to get the box to slide in. I wouldn't say it was difficult but it was much easier to get the box out than back in.

Ron

[foster461]

Well, I bloomed quite some time ago myself but my next door neighbor looks like he could lift the whole car if he had to and he is coming over tomorrow afternoon to give me a hand. Thanks for all the tips, I'm going to use them all..

 

Stan

[Andy Moltu]

The other mod that improves a TR6 clutch is a phosphor/bronze bearing carrier rather than a steel one,

I think the early cars came with these as standard. (The steel ones were the modifications made by Triumph to cut costs on later cars)

[Guest ron]

I think the early cars came with these as standard. (The steel ones were the modifications made by Triumph to cut costs on later cars)

That's my understanding of it as well, it certainly looks like a cost driven mod rather than an engineering one--------story of the motor industry!

Ron

[foster461]

The gearbox is in !. After 30 minutes of the brute force approached we fell back to something more scientific..

 

I removed the top section of the rear support bracket to allow for maximum wiggle room for the gearbox angle. Then we engaged the first motion shaft into the clutch plate which went fairly easily and located the rear flange of the gearbox ahead of the prop shaft flange so there was no obstruction to the gearbox moving forward. We were still a good inch and a half short of our destination at this point. Next I measured the gap between the rear engine plate and the gearbox bellhousing at the top and bottom and left and right and made adjustments via the jack supporting the engine and moving the gearbox left and right until I had the same gap all around. At this point I knew I had things more or less aligned.

 

With me under the gearbox just relieving the weight of the front end and my neighbor applying some leverage from behind (I put a short length or 2x4 across the rear section of the tunnel to lever against with a length of 2 inch hardwood dowel) the gearbox fully engaged with the clutch plate leaving just a half inch or so to go into the spigot bush. The gearbox fully slid home with just some minor wiggling.

 

After securing with a few bolts the gearbox and engine were then raised slightly to refit the top section of the bracket. My overdrive didnt come with studs to attach it to the bracket so I'm still waiting for these last bits to arrive to complete the installation.

 

It was a wonderful sound to hear the gearbox hit the rear plate after two days of struggling and the clutch lever etc is still working so nothing got hung up in the process. This is definately not a job to tackle single handed although having done this once I would be better prepared next time.

 

Thanks again for all this hints.

 

Stan

[Richard Crawley]

Congrats Stan

I also find the easiest way to do it is to lie underneath the gearbox with my head towards the front of the car, With someone else up top taking the weight. This alows you to exert the necessary forward motion & also see what's going on; not very comfortable but effective on most vehicles.

[foster461]

BTW I did use the dowels in the end. I started tightening things up with the bolts which were going in just fine but I noticed the holes were not perfectly aligned. Since I had bought the dowels I went ahead and inserted them and this brought everything into alignment. The drill trick would also probably work just as well and would allow the insertion of the bolts at 2 oclock and 8 oclock once the drill bits were removed. I guess I could drive the dowels out too but I plan to leave them in..

 

Stan

[foster461]

Progress report.. while the gearbox was out I used the trime to take care of a bunch of other refurb and painting jobs so it was only today that I was at a point where I could fire it up and check out the rebuilt gearbox and new OD. Amazingly after all the work on the rear oil seal and replacing all hoses etc it started up and so far no obvious leaks. I took it for a short test drive with just the drivers seat bolted down and the OD works !. It is wired up for 2, 3 and 4 and after verifying that all the interlocks were working I took it down the road and heard the sweet sound of the OD engaging.

 

I have a bit more rustproofing and painting of the floor panels to do before I put the trim back in but this is a huge relief.

 

The one thing that is not working right is selecting reverse. Even with the engine stopped it is hard to get it into reverse without mucking around with the lever. I'm hoping it is just a lever adjustment thing.

 

Stan

[foster461]

Well this is pretty embarrassing.. I pulled the gear stick out and looked at the selector shafts. The shaft for reverse is actually raised up about an eighth of an inch, maybe slightly more. So the gear stick has to be *lifted* (with some effort) to get it to engage. I call John who rebuilt my gearbox and he says that is correct, my old reverse shaft was worn out and was allowing reverse to be engaged by just slamming it over to the right and pushing the stick back. So for the last 20 years the gear stick has never needed lifting to get into reverse.

 

Oddly enough I checked the owners manual and it doesn’t mention any lifting. It just says “Move the lever sharply to the extreme right and rearward.. Engage only when the vehicle is stationary”.

 

Did the TR6 gearstick always need lifting for reverse or was there a change at some point ?.

 

Stan

[graeme]

Stan,

 

The 4A uses the same gearbox and the following is a quote from the glovebox handbook.

 

"Reverse is engaged by moving the gear shift lever to the right, lifting it and then moving it rearwards"

 

Graeme

[Richard Crawley]

Stan

As far as my experience goes, that's not right, I’ve never had to lift the gear lever to engage reverse. I've had my 6 for 30 years & during that time have rebuilt the original box twice & now have a different rebuilt unit (1 year) as the original was too badly damaged after the last of 3 lay-shaft failures. Engaging reverse in all of these units has always been by knocking the lever sharply to the right & then pulling it down. I just tried lifting & it has no effect at all on my box.

 

Incidentally, to ensure no more lay-shaft failures, I’m now using a box converted to take Stag radial needle roller thrust bearings rather than the standard bronze washers. This was done by an engineering firm in Essex who’s owner regularly races saloons & mods all of his boxes like this. You can use a Stag box instead but the ratios are different.