TR6 2nd Gear Bush Problem TR6 Looking at Steel

[Got_All_4]

My Tranny is at a LBC mechanical shop and he has been doing a rebuild. He doesn't do a lot of these anymore. My tranny commission number is CD26474. When he took the main shaft apart he discovered that the 2nd gear bush had broken. The attached washer or flange had cracked completely all around and fell off. He suggested going to an upgraded steel bushing. Looking at the tranny number in the Moss catalog we come up with part # 848-575. However this part on line Catalog does not show the attached flange.
Now I had an old tranny #CC95718 and the 2nd gear flange was good in it so he installed it and all the tolerances are fine but I'd still want the upgraded bush if possible. Now Moss shows a different steel bush that looks like the one that came out of the CD and the CC tranys. It's half the price too but more important will it work? Part # 330-300. I guess that's my question. The bronze one is 848-580.
Cheers!

 

[CJD]

That's the bushing we lovingly call the "top hat" bushing. It looks like 330-300 is a redesign with a slightly smaller brim. I see no reason it would not work, though. There is a chance the steel bushing wasn't getting enough oil, so they shortened the brim??

 

[Got_All_4]

so the difference between the 2 steel bushings 330-300 and 848-575 is the flange is larger on the 300?

 

[CJD]

That is what I get from the pictures. I see no reason the smaller "brim" would not work just fine...but I also don't know anyone who has used the new design.

 

[Got_All_4]

Ok here is another question. Searching You tube and internet don't remember where I saw it but he proclaimed that you have to replace as a set. Compatible 2nd gear for the steel bush. I think it was the Rusty Beauties Guy on You tube. He took out a bronze bush out of a TR3 tranny and used it. I have one out of a TR4 tranny but I'm concerned that it will do the same thing. I am now at the age where I can't R&R trannys quickly like I could in my younger days and my mechanic is older then me. With all my TRs I'm in a preservation mood. What I mean is no more racing or Autocrossing so they last. However I still will get into it occasionally.

 

[Hamish Racing]

Email these guys in the uk
Tom the son of Pete will help
They are a great company and really know their gearbox and axle stuff

Triumph Transmission Specialists

Expertise that has kept a generation of Triumph owners on the road and track.

petecoxsportscars.co.uk

 

[CJD]

Interesting. I don't know if they have had an issue in the past, but I would...and have...replaced the top hat in a used gear without issue. The purpose of a bronze bushing is to wear instead of the steel gear. I have not used the steel bushing, though.

When I studied the top hat, I think I came to the conclusion that the bushing was made too long, so the bushing, instead of the brim, took the load from shifting hard. I am pretty sure I shortened the bushing so the brim made contact first. In my mind the problem was a poorly designed bronze bushing, rather than the need to make it from steel. That said, there is nothing wrong with steel gear bushings. many tranny's I have rebuilt use steel.

 

[Got_All_4]

So which one? The steel top hat or the one with just the brim? I sent my tranny guy the above info from Hamish Racing.

 

[glemon]

When I rebuilt my transmission I ordered the later steel bush as I had read somewhere the steel was stronger. Vendor told me I was ordering the wrong for my box, and the older and new were not compatible. I think the catalog lists a cutoff point.

 

[Got_All_4]

When I rebuilt my transmission I ordered the later steel bush as I had read somewhere the steel was stronger. Vendor told me I was ordering the wrong for my box, and the older and new were not compatible. I think the catalog lists a cutoff point.

Was hat for your TR250? It would be the same for my early TR6. Who did you order it from?

 

[glemon]

It was either John Esposito at Quantum Mechanics or the Roadster Factory, 13 years ago, so not really sure.

 

[glemon]

Yes it was for the TR250

 

[mastaphixa]

I replaced the bronze top hat with a steel top hat when I rebuilt my TR6 box. Everything I read indicated that a compatible 2nd gear and different (thicker) distance washers were also required. So that's what I did.