[Fot] Triumph 4 speed O/D's and Layshaft bearing failures.

[Terry O’Beirne]

the brass bush is just 1 way of fixing the problem being discussed. That bush can either be fixed like in the pic, or floating, depending on the intended use

for the taper roller conversion, I make up a ‘stub axle” that presses into the laygear and then the bearing sits on that. I use a common wheel bearing. part number shown on pic of case. I’ll dig thru my photo file. Same bearing/method used at input shaft end except I have a shim plate there to adjust end float/preload

Without wanting to sound rude, this is not a conversion for the average “back-yarder”. It requires considerable engineering skill and accurate machining, eg, the big holes bored in the case must be perfectly aligned and bore right thru from 1 end of case to the other.

I gave up doing them for other people as they just take too long and people did not want to pay the hourly rate



From: Glenn Franco <brakey6666 at gmail.com>
Sent: 12 August 2019 09:46
To: Terry O’Beirne <tobeirne at skillpro.com.au>
Cc: fubog1 <fubog1 at aol.com>; gblake58tr3 at icloud.com; britcars at bellsouth.net; fot at autox.team.net
Subject: Re: [Fot] Triumph 4 speed O/D's and Layshaft bearing failures.

Very interesting!
Do you have a photo of the bearing install and do you use it with the bronze bush you installed in the Laygear?
Thanks
Glenn

On Sun, Aug 11, 2019 at 5:53 PM Terry O’Beirne <tobeirne at skillpro.com.au<mailto:tobeirne at skillpro.com.au>> wrote:
In all my years of having a business fixing hundreds of these boxes , I don’t think I ever had to resort to a pulling device like shown

I really am gob-smacked at what some of you guys are doing to these boxes!!

I totally agree, the rear thrust washer can be a problem. but a hook pick and screwdriver can usually pull up the most recalcitrant of these. In extreme cases a tiny Dremel grinder can then be used to cut thru the thrust washer once its exposed a bit.

In the 1970’s we mounted a die grinder in the tool-post of the lathe and then used a grinding tool in that to remove the outer shell of the bearing and then regrind the laygear to accept a bigger bearing or a bush. Once that rear laygear bearing has started to fail, the laygear gets very hard and conventional lathe tooling wont work, even tipped tools can struggle to get thru the hard layer. Over the years, the tooling got a bit flasher but the idea never really changed. Doing it by hand can be a disaster, because if you leave a ‘groove’ or dent in the laygear housing, a replacement shell type bearing will never last.

You usually can’t perform this repair with the later open cage bearings as the laygear finish and hardness wont be good enough. Its perfectly OK for a LG3 type bronze bush however…see pic below

I also include a pic of a gearbox case bored out to accept a taper roller at 1st gear end. Have done it to both ends with shim adjustment at front. Done plenty of these

[A hand holding a piece of metal    Description automatically generated]

[A picture containing ground, outdoor, transport    Description automatically generated]






From: Fot <fot-bounces at autox.team.net<mailto:fot-bounces at autox.team.net>> On Behalf Of fubog1 via Fot
Sent: 12 August 2019 03:49
To: gblake58tr3 at icloud.com<mailto:gblake58tr3 at icloud.com>; britcars at bellsouth.net<mailto:britcars at bellsouth.net>
Cc: fot at autox.team.net<mailto:fot at autox.team.net>; brakey6666 at gmail.com<mailto:brakey6666 at gmail.com>
Subject: Re: [Fot] Triumph 4 speed O/D's and Layshaft bearing failures.

HaHa that's pretty slick (insert thumbs-up)!

Glen


-----Original Message-----
From: Greg Blake <gblake58tr3 at icloud.com<mailto:gblake58tr3 at icloud.com>>
To: barry rosenberg <britcars at bellsouth.net<mailto:britcars at bellsouth.net>>
Cc: fubog1 <fubog1 at aol.com<mailto:fubog1 at aol.com>>; FOT list <fot at autox.team.net<mailto:fot at autox.team.net>>; Glenn Franco <brakey6666 at gmail.com<mailto:brakey6666 at gmail.com>>
Sent: Sun, Aug 11, 2019 1:26 pm
Subject: Re: [Fot] Triumph 4 speed O/D's and Layshaft bearing failures.
I had one stuck last year. This is the little pulled I made from 2 exhaust clamps and some all thread rod. Worked like a champ.


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