TR4/4A Clutch Decision Time

[TR Tom]

I’m at the beginning of a major engine/transmission rehabilitation project, so am starting to gather parts. While I haven’t got the full assessment report from the machine shop yet (praying for good news ), I do know my 20 year old clutch won’t be going back in. It looks like there aren’t many high quality clutch kits available for the TR 4 these days, but apparently there are lots more choices for the 4a (same as 6?) style.

Since the flywheel is at the machine shop anyway, would it just be a matter of having them drill for the 4a pattern so I could use either type? Would any other modifications need to be made? I’m assuming this would be an upgrade due to less rotational weight and lower pedal pressure. Any downsides?

Finally, any recommendations for brands and/or suppliers? The last time I did major work on this car, I got most of my parts from Roadster Factory and British Frame & Engine, both of which I had long trusted to sell me only the best quality parts. While both companies still exist, unfortunately Charles and Ken are no longer with us, so just wondering how things exist now.

Thanks for any advice,
Tom

 

[auprichard]

Yes - it is a fairly simple upgrade. You could also think about an upgraded (lightened) flywheel which will definitely contribute to greater driving response. I have done this with parts from Racetorations (www.racetorations.co.uk): they are high quality but disclaimer - they are owned by my cousin, Darryl Uprichard (NFI).

Albert is resurrecting TRF and has a pretty good inventory. He is always available to talk. Not sure about BFE.

Remember if you upgrade your clutch you will need the later throw out bearing and carrier. Good luck !

 

[mctriumph]

The early clutch (3 arms) uses the early flywheel only.Using the later clutch means later flywheel and throw out
bearing must be used. Try not to violate the cardinal rule "never fix things that are not broken" Personally I like
the feel of the early clutch......
Mad dog

 

[Rocky_LC]

There’s a lot of information at the Buckeye Triumph website regarding TR6 clutches (and issues with them).

Clutch — Buckeye Triumphs

www.buckeyetriumphs.org

I only mention this because you said the TR4A clutches was the same as the TR6. If this is not the case, then please ignore my post.

On my recent 5-speed conversion (1971 TVR Vixen 2500, with the TR6 engine), I did a lot of reading, and decided to resurface my flywheel, use a new clutch disk, double-pinned the clutch fork, used the Toyota (Koyo) throwout bearing, and I reused my pressure plate (with cleanup).

My engine & transmission had about 70K miles on them.

After a week, everything is running smoothly, but it’s very early, and I haven’t got a lot of miles on the setup yet…

Rocky

 

[TR Tom]

Appreciate the responses.

Did the math and realized even though it’s been 20+ years since I opened all this up last, it looks like only about 50K on everything. Clutch performance was one of the only things NOT wrong with this car. While the oil soaked disc is going in the trash, maybe I should just rehab the pressure plate, as I know it was a high quality part. As I said originally, it appears all the usual suspects are selling the same no name part, and basically say “you get what you get”. Anyone out there know differently? Kind of seems like taking a shower and putting on dirty underwear, but if the quality isn’t there, I don’t want to do this again anytime soon.

I’m definitely trying to avoid mission creep. I appreciate Dog’s advice. If I’ve learned one thing about old cars over the years, it’s that lots of “improvements” often arrive delivered on your doorstep packaged in a big can of worms! Never had a complaint in over 50 years of driving TR’s with three finger clutches, just figured a little lighter weight and more brands to choose from might be nice, and now would be the time to do it.

While I understand the benefits of an aluminum flywheel, that’s just not a priority at this time. I’ll probably have the machine shop take a few pounds off, but won’t be doing anything radical.

I’ve done a lot of research on this conversation since posting, and it seems the results range from very straightforward (as experienced by auprichard), to full on disaster. I suspect those who understand all the running changes done to these cars during production, and more importantly, know what they actually have, can pull this off pretty easily. Unfortunately, my 4 is a typical Frankenstein TR, that obviously lead an abusive and troubled life before it followed me home.

Glad to hear Albert is trying to make a go of TRF. If he has half the passion his dad had for the business, I will definitely try to shoot some of my dollars his way.

Any other opinions on the subject out there? I’m grateful for any knowledge you all can share.
Tom

 

[charleyf]

I will pose this as a question, as I do not know the answer.

If you lighten the flywheel , WIll you again need to balance all the moving parts? Or is this a small enough change that it will not affect the existing balance?
Charley

 

[TR Tom]

I will pose this as a question, as I do not know the answer.

If you lighten the flywheel , WIll you again need to balance all the moving parts? Or is this a small enough change that it will not affect the existing balance?
Charley

I’m doing a complete engine rebuild, so everything in the engine will be rebalanced.

 

[charleyf]

I’m doing a complete engine rebuild, so everything in the engine will be rebalanced.

thanks

 

[mctriumph]

Balanced as an assembly including the front pully is prefered. Also IMHO a fresh set of
forged steel rods makes for a happy motor. The prices have fallen and they are quite reasonable
today. Maxspeed rods, are much lighter than stock rods(cast iron) The cost of reconditioning the old rods
nearly offsets the new bits. Weight of reciprocating parts is what stresses the crankshaft and they do break.
A well balanced motor wants to rev, This is where the stock rods will kill a crank. Loads increase logarithmically
(balanced or not) with the RPMs. The 3 main crank will flex if the loads get too high, then BANG ya done!
Mad dog