jumping out of 3rd

[johnb]

When on the overun the gearbox jumps out of 3rdgear, if you hold your finger on the lever it stays in. Anyone had similar problems?

[TR5convalescent]

Hi John.

I had this with my TR5 about 10 years ago. There are adjustment screws in the top of the selector mechanism, but I cannot remember exactly where. Hopefully, someone else who has done this recently will be along in a moment. The gearboxes are very similar but the Stags' are stronger.

Don't over tighten as it makes the shift much more difficult.

[GDPR]

That sounds like a sticking plaster..... bet there is some endfloat in the mainshaft, weak hub detent springs and/or worn engagement dogs

[Guest]

yep, it's usually wear somewhere in the gearbox.

By now lots of the gearboxes are getting very "long in the tooth", and I'm routinely chucking away more than half the gears and hubs cos they are knackered out.

[flying farmer]

Sounds like the "properly reconditioned" Stag box I bought when fitting the Stag engine to my TR.

Getting fed up with the jumping out of gear I removed the top cover and checked the detent plungers. It is 20 odd years ago now, and there were either 2 conical plungers and a ball bearing, or vice versa on the 3 selector shafts. The grooves in the shafts were various widths according to the size of the ball/plunger that was supposed to fit in it.
The nub of the problem was that a wide ball/plunger was trying to locate in the narrow groove in the 3rd/4th selector shaft. Swapping the bits solved the problem.

I later found that the locking in forward and reverse gears at the same time problem that caught out the MOT tester every year was caused by the interlock plunger being missing completely from the selector shafts. Thank goodness whoever rebuilt the rest of the box did a better job of it!
Neil

[Guest]

I removed the top cover and checked the detent plungers. ....The grooves in the shafts were various widths according to the size of the ball/plunger that was supposed to fit in it.
..the interlock plunger being missing completely from the selector shafts.

Oh grief I went through all that stuff when I had to redrill and mix and match a load of TR/saloon covers last year adapting them from non overdrive to overdrive.
I was shocked to see when I took them to bits how the interlock plungers were missing from 2 of them!

Luckily our good friend Mick Dolphin had these tiny little parts in his stock as well as some unobtanium 2nd gear TR4/5 brass top hat bushes (the ones that always break!).

[johnb]

jumpingoutog3rdd

Thanks all for your tips, will try and sort it for next year.
johnb

[TR5convalescent]

Just one more thing. Is the gearbox noisy? That is does it sound like a car moving off in a 1950s Ealing comedy? If so then I'm afraid that Russ is almost certainly right and the box will need to be (properly) rebuilt. I had this with my 6 which, in short order refused to engage either 1 or 2, whether moving or not. Initially, after the noise started, it got progressively more difficult to engage 1 and reverse.

If it's still quiet, then Neil is probably on the right track.

I know a chap who rebuilt the gearboxes on my 6 and 5 who was confident enough to warrant his work for as long as o kept the car. I can PM his phone number if you PM me, but he might have retired now.

My 6 box had failed again within a year of being rebuilt by a well know supplier. This chap stripped it in front of me and the only bits worth saving were a couple of synchro rings.

[GDPR]

There is an element of "if it's not split in half, refit it with new bearings and hope" in the gearbox and diff world. 1-2 hubs have been unobtanium for donkeys, the new baulk rings are questionable and most seem to rebuild with metric bearings sourced from anywhere as long as they're cheap. I've also found some of the "new" layshafts variable diameter - some won't even go in the case!

You need to go to someone who has been at it a while and has a pile of corpse gearboxes he can cull bits from - I am surprised though with all the Stag, TR, Dolly Sprint, 2000 and 2500 cars still about that a new geartrain of decent quality hasn't been commissioned from one of the better Chinese firms - they are capable of good kit if you pay them the right money

[Guest]

1-2 hubs have been unobtanium for donkeys, the new baulk rings are questionable
I've also found some of the "new" layshafts variable diameter - some won't even go in the case!

The 1-2 hubs were born to die made out of monkey metal internally, made for the TR4 originally, a gutless wonder.
As soon as the pi models came along they wore like fury and became plain nasty at gear changes, the syncros were a nasty basic design with very poor oil circulation.

It was only when the Stag and Dolomite came along they fixed them and the syncros a bit better.

A little story from Germany from when I working at Cargraphic...
The advertising was "all new bearings and syncro rings".....the reality the new syncros were oval crap stuff so I never fitted a single new one in all my time there, idem the repro layshaft which were all crap too, so I fitted all good s/h ones.

What happened to the duff stuff?
It was all sold out the door to customers who wanted to rebuild gearboxes themselves, - soft layshafts, oval syncros the whole shooting match.
I kid you not!

I still have a selection of perfect s/h syncro rings which I use to rebuild people's stuff with good s/h OEM layshafts and later hubs and gears.
The gearchange always ends up being night and day compared with what their TR5 had before, so what do they know?

It's a system which has worked perfectly for years now, and I end up throwing most of their old tired gears in the bin.

[TR5convalescent]

I think that's why a lot of people are now fitting Ford type 9 boxes, but the cost of the kit is pretty serious.

[Guest]

When well put together, the Stag gearbox with its special stepped layshaft and double size bearings is not so bad.
You should use MOTUL full synthetic gear oil and it won't go wrong.

FORD type 9 is NOT & was never rated or approved for 170-200ftlb of torque, (3L engines).
Upgrading it properly is expensive.

The Sierra Cosworth had the MT75 which was still reckoned to be the main weakness of the car, while it was well known the planet gears on the LSD used to blow up under high torque.

Only the GETRAG 260 is really up to scratch, as it was an OEM, BMW (3L CSI), Opel (3L-24V), Jaguar 3.6L manual option.
There were special 262 close ratio units and direct dogs leg 5th options which make it quite interesting.

A kit has been put together to change the STAG to 5 speed Getrag.
That transmission will go on forever but the STD BMW ratios are not very nice.
I have seen it, but it is very expensive as it entails an entirely new specially made bell housing.

The STAG is as an expensive classic, not really a budget car, so probably well worth it.

[StagManiac]

Who supplies the Getrag conversion, Gareth? I am hoping that my Stag MOD 'box can be rebuilt without issues but one never knows until one gets into a job.

Paul

[TR5convalescent]

Hi Gareth

Is that the dog leg 1st as fitted to some Alpina E30s back in the era of gelled hair and double breasted suits? I was given a 323i with one of those as a courtesy car back in the day and wasn't really that impressed, but I suppose I'd have got used to it after a few weeks instead of a couple of days....

[Guest]

Who supplies the Getrag conversion, Gareth?

It's a friend I work with in Germany.
He's known as the GETRAG POPE!
In fact there is a smaller getrag which is also an interesting candidate for modification in this way.
I wish I had a photo, I was really impressed when I saw one in a TR6 the other day.

And btw YES, the dog's leg sport box was fitted to Alpina.
Alpina if your remember has BMW Works approval as a specialist tuning company to the brand.

I've driven a dog's leg direct top box.
The CR version is rocking horse poo, and it's true it's not easy to get used to in 5 mins!