2.5 Triumph engine: thrust washers

[Renaldo]

Guys, I was reading on a Triumph forum that the "thrust washer" problem with these engines (used in the 2500M) can be largely avoided by careful use of the clutch. For example, avoiding engaging and disengaging the clutch unnecessarily (at start up, when stopping and so on).

In fact, the writer suggested the thrust washers are not really prone to much wear at all, if the clutch is used judiciously.

True or false?

Ron

[Grantura MKI]

They have been known to "drop" into the sump. A terriable design IMHO.
Cheers,
D.

[spitfire4v8]

Adrian@ said:

Given that the fly wheel/clutch cover is part of the engine and the clutch plate is free floating on the splines of the input shaft and is in fact part of the gear box, how does the crank thrust bearing wear relate to the operation of the clutch? I can understand the rotating crank's want and desire to rotate and the thrust faces are there to hold it in place (given that the TR uses a crescent thrush washer rather than a full face washers and as above that this will wear and fall out) but not that the clutch operation affecting it.
Adrian@

Edited by Adrian@ on Wednesday 13th November 18:42

Not sure if serious, but .. when you press on the clutch you're pushing the whole crank assembly forwards against the thrust washer ..

[tr7v8]

Seen a few dead 6 pots with this issue. A few years since I worked on them but in those days it was cheaper to bin the engine & find another. Never seemed to be a rhyme or reason for it, a few did it, lots didn't.

[Renaldo]

I'm no expert, but I understood just as was stated: the clutch moves the crank against the thrush washers.

As I mentioned, some U.S. contributors seem convinced that excessive movement of that type, caused the thrust washers to wear out prematurely.

And that if the clutch is used carefully (not unneccessariy), you can delay any problem with the TWs almost indefinitely.

If it's true, I'm on board!

Ron

[Grantura MKI]

They can drop out from new. Drill the bearing "tab" and engine block and fit roll pins.
Regards,
D.

[RCK974X]

I have had several 2500 powered vehicles in my time, 5 different engines, PI and Carb, tuned and not, all with the manual box. I never had a problem with the thrust washers.

I did always make sure they were properly installed when doing a rebuild.
Just one of the engines I rebuilt did have some crankshaft float, and the washers were worn.

It is a terrible design really, all Triumph had to do was to attach the thrust washers to the end crank bearing cap, and then they wouldn't fall out. (seen that somewhere, can't remember which engine... Ford ?)

There was/is a lot of talk about how bad it is, and some owners would swear the thrust washers should be pinned to the block (not convinced).
There used to be talk about how some of the replacement clutch cover plates caused excessive wear (too much spring pressure), and you should always try to get an original cover plate, which was Borg and Beck, but I've never seen any proof of that rumour....

Agree with Adrian, measure the crank float with a dial guage (you can push the crank backwards, and then lever gently with crowbar or large screwdriver). The spec is given the workshop manuals, About 8 thousands max is my memory, probably wrong !

Edited by RCK974X on Wednesday 13th November 19:12

Edited by RCK974X on Wednesday 13th November 19:14

[Grantura MKI]

End float should be 0.004-0.008. Only motor that I have ever seen this happened to. Yes it was a P.I. lump, but do not think that matters.
Regards,
D.

[Renaldo]

Adrian, I'd send my car through the post to you, but packing it up might be a problem.

I think you better come and get it -- see you for a Winnipeg (Canada) winter shortly! Maybe you could even drive it home, except for those damn thrust washers, and the Atlantic Ocean.

Because of the all the handwringing I read about on other forums, I measured my end float with a dial gauge a few months ago. Came in at max allowable: .008.

I'm sure not going to tear the engine apart at this stage.

Car runs great! Adrian, you're getting a deal. Come to think of it, it's running so well, I think I'll keep it...

Ron

[Grantura MKI]

+1!

[RCK974X]

If you are worried, it's not that hard to get the sump off and replace the thrust washers with engine in situ.
(at least in a Triumph Saloon, not sure about a TVR)

[RCK974X]

Adrian@ said:

Ron...I thought you might find some way of wriggling out of me getting my hands on it, but it would be remiss of me not to offer to help you out of a sticky situation ...you do know that the combination of 2.5 engine and a TVR exhaust system is by far the the best sounding of the stock cars....IMHO of course.
Adrian@

There's nothing quite like the wonderful sound of the Triumph 6 on song....I had a twin pipe version with free flow exhaust manifold, and it STILL sounded wonderful.

[Renaldo]

Andy, there's a TR6 owner in the U.S. who has done it (with the engine in situ), and has recorded the whole process with photos.

You're right -- it actually doesn't look too tough! In fact, removing and replacing the sump looks to be the most difficult part of the process.

Ron

[heightswitch]

Renaldo said:

Guys, I was reading on a Triumph forum that the "thrust washer" problem with these engines (used in the 2500M) can be largely avoided by careful use of the clutch. For example, avoiding engaging and disengaging the clutch unnecessarily (at start up, when stopping and so on).

In fact, the writer suggested the thrust washers are not really prone to much wear at all, if the clutch is used judiciously.

True or false?

Ron

Load of bks spouted above
Centre thrust washers rotate as they wear moving around the bearing journal to the bottom surface then drop out into the sump.
Many racers fixes over the years including pinning (white metal) them to the journal and fitting 2 sets so the rotation issue can't happen.
Its just a design malady of the engine and well known.
Just check thrust now and again to ensure everything is OK. They are a diy job. Adrian is correct..most TR6 owners have one on their key ring if they are a proper enthusiast..

Jelly will have plenty experience of this and the fixes...as ever race cars, high revs, higher pressure plate clutches etc had an effect on thrust washer life.

Edited by heightswitch on Wednesday 13th November 22:21

[Slow M]

RCK974X said:

Adrian@ said:

Ron...I thought you might find some way of wriggling out of me getting my hands on it, but it would be remiss of me not to offer to help you out of a sticky situation ...you do know that the combination of 2.5 engine and a TVR exhaust system is by far the the best sounding of the stock cars....IMHO of course.
Adrian@

There's nothing quite like the wonderful sound of the Triumph 6 on song....I had a twin pipe version with free flow exhaust manifold, and it STILL sounded wonderful.

Six into one into two fabricated tube manifold and twin Flowmaster silencers. Gorgeous sound that used to frighten a buddy, whenever I pased him, in his Elan +2.

Best,
B.

[Hansoplast]

Having a TR 250 for 16 years and restoring it bottom up, driving it through Europe over all high mountains, I had to change the trust washers only once.
Keeping your foot of the clutch (unnecessary) when standing for traffic lights helps.

Luckily more good reviews for the six cylinder are given in this
Mine had a 6-2-1 header with one muffler and end pipe. What a sound.
The double end pipe is called a wheelbarrow over here.

If the TVR with its Ford Kent engine brings me as much fun I am very happy.
Wondering what he has in mind for me (breaking I mean).

Hans.

[sarbec]

[sarbec]

[Renaldo]

Guys, I couldn't agree more about the wonderful sound you can get from that engine. And whether it's of much help or not to the TWs, I try not to use the clutch excessively.

My 74 2500M has the standard manifold, with a single pipe outlet -- running through a Thrush "cherry bomb" and a Magnaflow stainless steel muffler right at the end. I tried a few combination, before settling on this one. It's good!

It's not terribly loud in normal driving. Although my wife always says she knows when I'm nearing home -- she says no other car sounds quite like it.

Get the revs up, and it wails! As I'm entering the motorway from an off-ramp, revving away, I'll bet I'm scaring the living daylights out of anyone nearby.

Ron

[Grantura MKI]

GWG. This is a design fault and should be addressed on a rebuild.
By cranky!
D.