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Triumph TR6 - Thrust Washer Mod. -- Rimmer Sale Contiues

I've a question for you all : I'm installing new all bronze thrust washers in the upper rearmost position as well as machining the rear main bearing cap to accept an identical thrust washer/bearing. It seems like a good idea to 'pin' the upper washer by drilling the block to accept a hollow dowel pin that goes to the oil gallery that feeds the rear main bearing so that the thrust bearings will be lubricated without relying only on 'splash'. (I will use at least one, probably two other pins in a softer metal than the bearing bronze in both upper and lower thrust washers). Have any of you actually done this modification ? Your results/observations ? Also, if I "pin' the upper thrust washer/bearing the only way to replace that washer/bearing would be to remove the crankshaft. The machinist that I am working with on this project sees the 'pinning' and the machining of the cap as a way of "solving the TR thrust washer problem" and that it shouldn't need to be even considered until the next major overhaul - 50,000 - 75,000 miles. I agree with him in principle but am still a bit leary of solutions that force major surgery in the event of a recurring problem. Opinions based on experience would be appreciated.
Interesting/Depressing Note : Six years ago the previous owner bought the car and immediately started reading religously the 6-pack and vtr sites/lists. He was alarmed when he read of the TR6 thrust washer "problem" and quickly took the car into a local shop to check/adjust --He was quite happy with the way the car drove and so was I --(I bought it !) until I took the crank out and found that that "shop" had put the thrust washers in backwards. The "interesting" part of this comment is that when I decided to buy a new crankshaft I found out that Rimmer Bros has extended it's free shipping special to the States till Dec 31 and a brand new , Stanpart 'old stock' crank cost $195 delivered to my door in Seattle. I ordered it on the Rimmer website at midnight on Sunday night (8am Monday morning in London) and received it on the next Friday morning at 9am !!
**I am truly an English car 'nut' when I think fondly about what a "deal" I got on my new crankshaft for an engine with 65000 mies on it . So it goes...
David Johnston

Hi David

It's amazing that the basic engine was left with the odd weakness in design after so many bolt-on improvements over the years (built in obsolescence? / looking after the future of the maintenance industry?)

The question of lack of oil to the the thrust washer maybe somewhat overstated as the cause of wear/failure.

The basic design is not what it should be. Why have 1/2 a bearing surface when you could have a full one?

Opinion here is that modifications to the end cap should be done so that you form a bearing area above AND below the shaft. You should double the life and have more tolerance before serious damage is done as it's the retaining flange on the bottom cap which is the bastard that gets you.

This can be done by machining off the retaining lip on the bottom cap and fitting a simlilar bearing material as the thrust washer. Easiest would be to pin horizontally into the end cap but there are risks of losing both if the pins shear.

Better, but trickier, would be to machine a rebate into the side of the cap and then pin a thicker 'thust washer' into position. Either way, you don't have to remove the shaft when changing.

Your thoughts about extra oil are good (you know how I feel about oil!!) but it may be a lot of trouble for not much improvement in lifespan.

Cheers
Roger
Roger H

Hi David
I agree with your concern over pinning the thrust washers. Much has been written about the "problem" and the supposed cure which, in my opinion, creates another problem which I think is probably worse! Replacing the thrust washers (a wear item) is really not too difficult a job - once the washers are pinned you need to do much more work to replace them. I think that perhaps the TR thrust washer should be looked at as good engineering!
Michael

Here's some info on an alloy thrust bearing. Sounds interesting, and can be made to any thickness, I believe.

http://users.arczip.com/zntech/tr6.html

BB
Brent B

hi Roger,Michael & Brent --thanks for your comments/suggestions. My "all bronze"
thrust washers from Scott Helms (arczip.com)(Brent - he's in Indiana!) should arrive today or Monday. My reason for posting this was that I'm curious how others have done the actual machining and whether pinning/doweling/oiling solved or created other problems. I've always (17 years driving a TR6) seen the thrust washer adjustment process as a "maintenance thing and not a 'problem' per se" - agreeing with Michael - but now that I find myself with a ruined crankshaft and in the midst of a complete rebuild , it has become a 'problem' that should be solved (for the reasons Roger stated)-- IF it can be done with good results.
David Johnston

Update: The bronze thrust washers arrived today and are beautifully made - they are the exact thickness I ordered and were received in 4 days. They fit the channel in the block perfectly, are 7.4mm wide rather than 5.5mm so provide a much larger contact area with the crank - overall a quality piece - $15.00 each including delivery in the States. (No financial interest on my part.)
Next , machining the cap - any experiences to share ?
David Johnston

Hi all,
I think it is a good idea to monitor the thrust washer condition by checking the crank end float periodically using a dial gauge. Once you start seeing increased float then you know you should perform the task. Presumeably that would prevent the expensive repairs. The improved thrust washer looks like a good idea.
regards
Michael

David,
I watch this thread with more than mild curiousity, and you probably understand if you have seen my previous posts. Please keep us informed about the progress. I am slowly gathering bits to rebuild my original engine, and am considering options.....

Thanks,
Rod
Rod Nichols

Dave-I made a fixture to hold the bearing cap in a lathe and have machined the cap for a thrust washer. This was on an old spare block and I have never used it. It seems that pinning or milling a retaining slot in the cap would be a better choice as it would allow changing the upper TW without removing the crank.
Berry Price

This thread was discussed between 05/12/2003 and 08/12/2003

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