Rear oil seal et al

[foster461]

This spring I'm going to remove the gearbox to fit an overdrive and at the same time replace all the clutch parts. I'm wondering what else I can reasonably get to while the gearbox is getting rebuilt. For example is the rear engine oil seal easy to get at and replace while I have everything apart, and is there anything else I should be doing at this time ?

 

Stan

[Guest ron]

Stan

Worth doing the propshaft UJs while the box is out, they're a pig to get at otherwise.

Still a fair bit of work to do to reach the rear oil seal once the gearbox is out, ie remove flywheel, engine backplate, sump and seal carrier.

Ron

[CP62]

Stan,  

 

Have you got a rear engine oil leak?  If not, it may be better to leave well alone and not disturb the seal.  I agree with Ron's recommendation on the prop shaft UJs though - it's a good opportunity and a badly out-of-balance prop can be very destructive of gearbox/diff bearings.  

 

I don't know how you feel about modifications, but you could also consider getting your flywheel balanced and lightened.  A lightened flywheel will give you quicker engine response/pickup and will make the car feel a little quicker, besides reducing stress on the crank.  It's better to get all the rotating parts balanced together, but just doing the flywheel when it's being lightened will do no harm.

 

All the best,

 

CP62

[foster461]

Well the gearbox is out and it having an OD fitted during the new few weeks by John Esposito in CT. The bellhousing has a thick layer of congealed engine oil covering the entire surface so I suspect that the rear oil seal is going to have to be replaced. I was planning to remove the flywheel anyway to replace the pilot bush so I'm only a couple of steps away from that rear seal at this point.

 

I'm having a problem figuring out what I will need in the way of gaskets though. It looks like there is a gasket for the rear seal cover, and if the sump has to be dropped there is a gasket there as well. Is that it, just the seal and these two gaskets ?

 

Stan

[Richard Crawley]

Stan

If you are having GB rebuilt, just make sure you get a good recon job; it’s worthwhile considering having the thrust washers converted to Stag radial needle roller spec.- machining of the casing is required. The standard bronze thrust washers are very marginal on the TR6 (especially on the 150 BHP) which is why Triumph modded the box for the increased torque of the Stag V8. Unfortunately, you can’t just replace the 6 box for a Stag cos the ratios are different, although I suspect there may be lots around running like this!

 

Watch which clutch parts you fit; some of the stuff being sold as ‘original Laycock’ is not what it purports to be & there was some **** B&B stuff running around only a few years ago (& probably still is), including stuff supplied by some of the major TR suppliers; there still seems to be some residue getting passed on to unsuspecting buyer! I would add that there is absolutely nothing wrong with B&B if you can avoid the ****. I currently run a recognised ‘good one’ with absolutely no probs at all; you just have to make sure you don’t buy the wrong one!

 

I would also replace both the cross shaft & the yolk - regardless of how good they look! Get an upgraded yolk taper pin & lap it to the shaft; fit new ‘Glacier DU’ bearings to the gearbox casing & fit 2 bearings to the actuator end instead of the standard single bearing. Do all this to get it right & your box & clutch will be as smooth a silk, but more important, it won’t fall apart after a few thousand miles!

[foster461]

I will probably stop short of upgrades that require mods to the case but the guy who is doing the work has an excellent reputation here in the US and he did suggest using a longer rear cluster bearing to beef up that notorious weak spot. The clutch parts I plan to use are from The Roadster Factory, they have their so-called "magic clutch" combo that includes new shaft, fork, pin and release bearing. TRF also has an excellent reputation here for selling the best parts available or at least putting a health warning on anything they cant stand by.  

 

My current gearbox has done 80k miles and it looks in great shape with very little end float on the mainshaft so I think even the bushes are still good. I agree the thrust washer design is primitive but these days I'm lucky if I put 1000 miles a year on the odo so I'll be long gone before anyone has to worry about this again !.

 

It is going to be great to have an overdrive once again after almost 20 years.

 

Stan

[Red 6]

Hi Stan,

 

I fitted a new clutch and re newed the engine rear oil seal last week end.

 

The seal is simple to replace, but you "HAVE" to replace the sump gasgate at the same time. The brown book actually says be very careful when removing the rear seal housing so as not to damage the sump gasgate what it should say is that whilst removing the seal carrier you "WILL MOST DEFINITELY DAMAGE IT"

 

The process to change the seal is

Remove flywheel 4 bolts

Remove engine back plate 7 bolts

Remove seal carrier 7 bolts (top one has a copper washer)

push out seal

Push in new seal

Remove sump 23 bolts(drain oil first)

Clean everything with degreaser and re assemble

 

fit clutch, gearbox, propshaft, wiring tunnel,

 

go for a test drive.

 

By the way the oil you speak of could be the main shaft oil seal (easy to fit)

or the paper gasgate behind the 2 bolted plate below it, or the release bearing has shed its grease (as in my case) or the rear engine oil seal.

 

Oh yes dont forget to add oil ::

 

Let us know how you do

[foster461]

Excellent, thanks for the info. I have ordered the bits and also some crank thrust washers just in case..

 

I'm pretty sure this is engine oil and not something coming out of the gearbox. There is a lot of it, more than could be thrown off the release bearing, there is no sign of leakage around the input shaft seal or the countershaft cover and it looks and feels and smells like engine oil not 90w gear oil which is what I was using.

 

Stan

[Victor1155]

Hi Stan

 

I carried out the same procedure a little while ago and considered what else to check/replace whilst the gearbox was out and as there was a weep of oil from behind the flywheel decided to change the rear main oil seal. At the risk of castegation from the rest of the readers of this most marvellous source of knowledge and information I removed the oilseal from its housing with a lip seal puller and, with the new oilseal liberaly coated in oil, tapped the new seal into position. The engine has covered some 4000 miles since and I happy to say it is still oil tight at the flywheel end. Whether I have been exteremly lucky I don't know but it did save a whole lot of work. If you do decide to replace the rear oil seal when you take out the last flywheel bolt and are ready to remove the flywheel from the crank remember it is heavy and you don't have a lot of room to manoeuvre yourself.

I will now sit back and wait for the fallout good luck which ever way you decide to go for it.

 

Victor 1155  

[foster461]

Victor, are you saying that you managed to remove and replace the seal without having to remove the rear plate and the seal housing ?.

 

Thanks for the reminder about the flywheel weight, I'll make sure it has a soft landing in the event that I drop it..

 

Stan

[Victor1155]

Hi Stan

Yes thats right, all I did was to use a lip seal puller, which you can make yourself, and pull the seal out. When installing the new seal liberaly coat both the 'lip' of the seal and the 'case' of the seal with oil etc and using a piece of hardwood tap the seal carefully into the housing ensuring that its enters the housing squarely. It may be helpful if the piece of hardwood is shaped to the thickness of the front section of the seal so to aid tapping it into the housing passed the engine backplate. As in the earlier post the 6 has done approx 4000 miles since and no leak. The reminder about the flywheel is justified as it took three weeks to get the full feeling back into my fingers when it fell on them!

You can always give this method a try before going to the extremes of sump, engine back plate and seal carrier removal. I know that time dulls the memory but I am certain that this is the procedure that we used to carry out in the Triumph workshop back in the 70's when I was an apprentice.

Best of luck.

Victor 1155

[Red 6]

hello all,

 

There are 2 types of rear oil seal that i know of and on my 250 it had a lip as opposed to a hole, if that makes sense.

 

The whole job only took an hour (inc the sump gasgate, cleaning the sump ugh! and the parts and 2 cups of tea).

 

My flywheel is lightened but even so is still quite easy to handle especially when you are on your back under the car!!!!,

the real effort is lifting the box back in from that position with just the wife holding the od end of the box.

 

Oh what fun we had.

[Victor1155]

Hi Red 6

 

"the real effort is lifting the box back in from that position with just the wife holding the od end of the box."

 

Was that the odd end of the gearbox or the overdrive end?

Victor 1155 ???   ???

[foster461]

Well, the growing puddle of oil on the floor directly under the flywheel is confirming that I have a leak somewhere on the back of the engine so that seal is the most likely culprit.

 

When I removed the gearbox I put a trolley jack underneath to support it and I had a pretty easy task of basically lifting the rear of the box slightly to clear the mounting etc and it just slid backwards with the jack and I lifted it out. The od will add some weight and bulk but I'm hoping a similar technique will guide it back in.

 

Stan

[foster461]

I do have one other question... I was reading some articles about clutch problems and it was asserted that people who omit to use the two studs to locate the gearbox on the engine plate and instead use bolts are more prone to clutch release issues because the gearbox can rotate slightly. When I pulled my gearbox out there were no studs, only bolts (of different diameter). I wonder if the studs were used on all model years or if mine were replaced with bolts at some time ?.

 

The dowels are supposed to be located at 2 oclock and 8 oclock.

 

Stan

[Red 6]

hello again,

 

I think the stud issue relates to the location of the clutch cover on the flywheel. Sometimes over the years the locating dowels "vanish" and the clutch cover is bolted up without those dowels. What happens then is the clutch cover quickly becomes mis aligned as the energy? from the flywheel moves the cover out of true. The result is definitely clutch release problems.

 

The studs on from the engine are at 12, 1, and 11. To help align the gearbox you shoud find the longest bolts you can 3" is good, cut the head off and insert the threaded ends in the stud holes at 11 o clock and at 1 o clock. By doing this the box has 2 fixed points by which to be guided into place. Afterwareds just remove the studs and replace with the origionals.

 

Good luck, and sorry about the grammar i am tired and off to bed ::

[MRankin]

Stan,

There are two (if I recall) 5/16" dowels that locate the rear engine plate to the engine block. I made my own by using the non threaded neck of a long 5/16" bolt. The previous post is correct in there are studs from the block to the bellhousing but typically the bellhousing holes are not so round and larger than the bolts. This can  create a slight misalignment of the input shaft to the rear pilot bushing. By properly aligning the rear engine plate to the block you remove one area of problems.

 

Yes there are two bolts from bellhousing to rear engine plate that are larger in diameter. I think 7/16" instead of the several other 3/8" bolts for the rest. These two larger bolts help to properly align the bellhousing to the rear engine plate.

 

My thought process was....I better do all I can to eliminate possible clutch engage/disengage issues while I have it all apart. I installed the TRF Magic Clutch Kit as well using the additional recommended parts. I have had no issues what so ever with my clutch. Do you really want to take that all off again and be without your TR6 for another weekend?

Good Luck!

[foster461]

This is what triggered my question, snipped from a doc by Nelson Riedel before he withdrew all of his content from the Buckeye web site:

 

Important! Prior to installation make sure the two dowels between the engine plate and the gearbox are present.  Missing dowels can cause rough jerky clutch operation as the release bearing is not centric to the clutch (See drawing)

The same applies for the two dowels between engine and engine plate.

 

This is accompanied by a drawing of the dowel location and they are on the gearbox side of the engine plate.

 

However.. I have checked all the reference material that I have (haynes, bentley, my gearbox and engine, spares catalogs, this forum etc) and I cant find any corroboration that these dowels exist..

 

Stan

[jonlar]

Hi Stan, yes, they (the holes) exist!   Well at least on my car, just been out and checked G/B bell housing and engine back plate, and they're there - 0.375" on my vernier.

 

One hole, is 3 above the starter motor housing and the other almost 180º opposite but on the high side.    I may be wrong, but I believe dowels were omitted from the 5s and 6s, and they will locate the G/B better than the assembly bolts on their own.   My intention is to use a couple of twist drills in them, to help get G/B in right position.

[foster461]

I posted (without permission) Nelson's diagram.

 

http://www.rollingcat.com/TR6-Home.htm

 

Scroll down to the bottom.

 

His original article has the title "TR250/TR6 Reliable Clutch" so I wonder if this was an early model feature that was later discontinued in favor of bolts ?.

 

Stan

[MRankin]

Stan,

Jonlar is correct on the size as 3/8" (0.375") for the bellhousing bolts/studs. I typed incorrectly. The rest of the bolts must be 5/16" then. I knew a couple were larger. It also makes sense to tighten these two 3/8" bolts first to nearly snug before tightening the rest of the 5/16" bolts to make sure all is centered correctly. Granted I do not have many miles since my TR6 got back on the road (about 500 miles now) but it operates smooth as silk and pedal is easier to press with the TRF kit than the B&B I removed. Cheers!

[jonlar]

Nelson's engine back plate diagram is spot on.   I'm sure I read somewhere that dowels were fitted on 4/4As etc but omitted from 5s and 6s??   Can anyone confirm?   They are certainly useful for alignment purposes.

[foster461]

Moss in the US lists this as:

 

325-205  $6.95  DOWEL, engine plate to gearbox, 2 required

 

Not much ambiguity there..

 

http://www.mossmotors.com/Shop/ViewProduct...teIndexID=32713

 

Their printed catalog shows this dowel on the gearbox side of the engine plate, maybe they moved it for the web diagram to get it all to fit in the desired real estate.

 

Stan

[jonlar]

In the Moss Uk 5/250/6 parts catalogue in "External Engine" pages, these dowels are shown as item 20, Part No. DP612 - Dowel Pin, rear plate locating - 2 required.   Are dowels required to locate the back plate (not removed mine), or are these mis-labelled?

[Guest ron]

Mine had no dowels when I removed the gearbox, but the holes were there for them, I'm inclined to agree with Jonlar these dowels were probably not used in the 6, dowels don't usually get lost as they are quite a tight fit [pointless if they aren't], and I would be surprised if anyone would go to the bother of removing them just to chuck them away.

Tom Freemont posted a good method of aligning the box and engine a while back, worth searching the archives.

Ron