TR4 gear box,...some help for a frog eater?

[lagoon]

Hi Ladies and Gentlemen,

I apologize for my English, I'm French ( nobody is perfect );

I often read the TR Register forum and hesitate a lot before facing the devastating effects of my English, (not from Cambridge if I remember my teachers).

I present myself ( probably not the right place for that )

I’m 67 years old, leave and work in France as a doctor, specialized in Chinese Medicine. I drive English cars from the beginning of my driver’s life (Fifty years,..My God! ).

Several Mini, 3 Jaguars MK2, an E Type serie one roadster, RR Silver cloud serie 3, Range Rover, …To days I drive a S type V8 from 2002…and a mix of other european classic cars.

But the most important for me, right now, is to achieve the restauration of a 1963 TR4. I began in 2013. It’s a TR4 of 1963; engine, carburetors, inlet manifold, soft top,… and other details are from TR4A. To my mind, only frame, body, suspension and brakes are TR4 ones.

For the first trial on the road, last month, on road we did face a problem with the gear box on which we did a lot and expect good results.

The problem of my box is: third gear jump off when deceleration. We have controlled the two hubs, changed four synchronizing rings with good ones, good bearings to, springs and balls into the hubs, and into the tree cover shafts, controlled the clearances,...the problem continues. We are wondering about a problem with the input shaft ( main shaft and countershaft seem to be correctly fitted ).

OD runs correctly

Gear box and OD sound coming from a saloon: But,….Even if we did look obviously for a suffix corresponding, we got no success.

Here are all the numbers we found on the gearbox case

On a place:

GR105607A and under something like: 8G76

On another place:

88306828SM and V2947

My first question is: where does this box come from?

The second;…Does somebody understand the trouble of my box?

Thank you to help me

Kind regards,

Charles

[stuart]

GR numbers usually denote a factory rebuilt gearbox from back in the day. Have you tried without the gear lever gaiter in place as some of the repro ones can be too tight on the gear stick.

Stuart.

[BlueTR3A-5EKT]

Welcome Charles.

 

I too have a 'jumping out of 3rd' issue when my gearbox is cold. after 10 miles all is fine.

 

As Stuart has written a gaiter that is too tight may be causing some problem - remove it and see if it helps.

 

Another area may be the remote linkage in the top cover. Here is an excellent article that will help.

http://www.buckeyetriumphs.org/technical/Gearbox/GearboxCover/GearboxCover.htm

 

Cheers

Peter W

[lagoon]

thank you for your answers.

I think the problem is beyond the gaiter.

The cover off, when we push the hub of the first/second gear, it correctly locks on. tight.On the contrary the Third never completely engages and can slide back with a two fingers light pressure on the hub.

I read the excellent article of buckeye.

It sounds like the 3th gear hub course is blocked forward somewhere. about 2 mm actually lack to be correctly engaged.

Edited August 13, 2016 by lagoon

[boxofbits]

To me it sounds like wear on the 3rd gear itself, or detent plungers/ springs on the hub, and maybe the laygear, but you need to check selection, and as Stuart says, for any obstruction stopping the gear going fully in.

 

Regards

 

Kevin

[ChrisR-4A]

Check the area below the bottom of the gearlever, is the anti rattle spring and plunger still in its hole?

[MichaelH]

Triumph in their wisdom made subtle changes to the third/fourth sincro hub between the the TR5 and J type TR6 boxes

If you can get a late TR6 3/4 sincro hub you will find it sorts the problem of third gear falling out of gear on the overrun

Bon Chance

Michael

[lagoon]

Hello Gentlemen,

Tank you for your answers. I begin to approach an effective understanding of the problem.

Regards.

[lagoon]

Hello,

I spent a lot of hours reading the technical chats and other posts. I think I've found. Actually my gearbox probably comes from a Dolly sprint. I'm waiting for a deal with Overdrive Repair. Of which I hope a new GB with OD corresponding to a TR4. I'm wondering about my car what is really corresponding to a TR4. It's a transgenic hybrid.

Thank you for the help

Regards

Charles

[lagoon]

Hello,

One more time, I Thank you for the help.

Concerning the box,...

After a lot of questions, we did change somme shims between the differents hub on the shafts. Now, the box sounds correctly lock on the third gear. We shall be sure of that after a trial on the road, when the engine will be completely rebuilt.

Krankshaft has genuine sizes, but has to be machined because a light ovalization. About head, I was wondering enforced seats for exhaust valves, I' have read a lot of forums and decided to skip this step. The professional worker was not quitte easy with the very small space between the two holes of valves and the thinness of the seats obtained. (My E Type, restored twenty years ago has run 100.000 km with additives, an runs perfectly today on the french road since I sold "her" to my best friend).

Sleeves and pistons are 87mm, from TR shop ( good adress), County set with Grant rings.

Pistons and conrods will be weighted and équilibrated. All the mobile assembly concerning the krank, from the fan extension to the complete clutch, will be dynamically balanced.

As you see on the picture of my avatar, my TR 4 has a grill of 4 and front wings of 4A. A distraction of the man which rebuilt the body's parts. First, I was desapointed. On the other hand I definitly accept that my car is an hybrid. I shall have probably to accept ungracious remarks of "ayatollahs" of perfect authenticity.

" That's all folks",...

.... and Thank you again for the very spirit of friendship on your nice forum.