450 SE Gearbox

[Henry Harris]

My gearbox is in need of an overhaul. On stripping it down, it appears that some components are of a heavy-duty type. It may have been an original uprated SD1, or it was how TVR produced it. The usual contacts are drawing blanks. Are there specialists out there?

Thanks

[JR]

Henry Harris said:

My gearbox is in need of an overhaul. On stripping it down, it appears that some components are of a heavy-duty type. It may have been an original uprated SD1, or it was how TVR produced it. The usual contacts are drawing blanks. Are there specialists out there?

Thanks

Have a chat to Andy :-)

andymadmak said:

mikeb said:

L33 said:

Daz,
Give Ken Tomlinson a shout. He works over at N&T Transmissions in "Over Whitacre" near Nuneaton.

From the much research I did last year, Ken is THE man when it comes to the LT77 box and what can be done with it.

If I can find his number, I'll text it to you.


L33

Just try getting hold of him though!

MikeyB

Yes, its a bit tough. Best time to call is about 6 ish. Ken did my box and he did a great job. Mind you, he should know what he's doing, he designed the unit for Rover/Triumph!
Ask him to tell you about the decsision to go with ATF fluid instead of gear oil - it's a hoot, and a brilliant example of how management should not make an engineering decision !

andymadmak said:

tvr4ever said:

A few years back the people from Castrol advised SMX-S for this box. When you ask them now they will tell you to use a different oil. (at least in Germany they do)
They now advice you to use Transmax-Z oil for the Rover box. I can only speak for myself, for me it made a huge difference in gear selection smoothness. I use to go quickly through first and second gear before engaging reverse, with the new oil there's no need to do that anymore. All in all a big improvement over the old SMX-S oil in my opinion.

Fred

But isn't Transmax-Z an ATF fluid? If so, then it ultimately will produce the same problems that using ATF fluid always does in LT77 boxes - wear and failure!

The box was actually designed to use Motul 75 gear oil - I got this straight from Ken Tomlinson who was on the design team for the box at Leyland. Early SD1s had gear oil, but (lady) owners complained that in cold weather they could not change from 1st to second for the first few miles. The switch to ATF was a bodge - and one which was to cost BL dear when box after box failed. Its worth noting that all the racing Rovers and rally cars that used the box all used Motul or equivalent.
I grant you that Transmax may be a super duper ATF, and perhaps it will not create so much wear as an older type ATF, but its still an ATF and so I'd be wary. A few miles of cold start slow shifts is a small price to pay when compared to a rebuilt box!

Andy

andymadmak said:

Actually the handbook for my wedge specifies S.S 80 (thats how its written in the book) for the gearbox - not ATF. I can scan it in and show it here if anyone's that interested.

I appreciate that everyone keeps referring to the Rover spec, but the Rover spec is wrong according to the man who actually designed the gearbox! As I said before, the use of ATF was a bodge to improve cold shift characteristics. High torque applications cause heat and wear in ATF filled boxes. Ken Tomlinson told me that many LT77 running ATF are so badly worn that they are beyond economic repair - especially if the car is either used to tow a caravan, or if the car uses a higher performance engine (like a TVR) which takes the box closer to it's torque limits anyway.
If it were me, and given how easy the job is to do, I would switch the lubricant.
As a matter of interest I also spoke to Richard Thorpe on this subject a few years back, and he used to make up a blend of oils for wedge gearboxes rather than use ATF

Andy

[adam quantrill]

I used to use a mix of SAE80W and ATF but now I'm on SMX-S. It must be good because I haven't blown up the box on the 400SX yet!

As for your heavy duty parts - it might be that the bearings have been machined out for larger ones, that's an upgrade that I have heard of in the past.

It should be easy enough to press them out and put in new ones, you just have to identify the right replacement.

[rev-erend]

Adam - you gearbox was wineing nearly as much as your superchatger..

Henry - I'm having my gearbox rebuilt and strengthen at Competetion Transmissions nr Hatfield Hertfordshire.

The did Steve Heaths box a few years back.

http://www.gearboxman.co.uk/contact.html

[mikeb]

But you ain't had it back yet though have you!........................................................ When you 'eventually' do, see if the mounting holes are a different size......................!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!! ;-)

Good luck.

MikeyB

[rev-erend]

Mike

I've not taken the box there yet (planning to on Monday) .. if you had problems there - would you email me details. THKS.

[adam quantrill]

rev-erend said:

Adam - you gearbox was wineing nearly as much as your supercharger..

... but not as much as my missus on the way home!

I have a feeling that some of the box is straight-cut.

[tempus]

When the box came out castrol ep80 was the oil on the applications chart,shortly to be replaced by atf,I spoke to the oil companies tech. depts. at the time as I thought they had made a cock up and printed an error but both Castrol and Duckhams said the same thing "the reason for the change in spec.is excessive whining in the transmission and the thinner fluid reduced this",when asked who had come up with this they said it was from Rover direct.I believe they also took responsibility for any warranty problems as they had overidden the designers recomendations.Tempus

[TVRleigh_BBWR]

Does anyone know yet what the best thing to put in it. as will be using a LT77 in the race car.

Don't car about noise, plus it will be warm before use.

Need a nice change when warm though, and not fook the box. as it going to be pushed hard. with 230-240 REAL BHP.

[shpub]

With only 230-240 real bhp, it is not that important as it isn't really that big a stress.

The big factors will be how violent the gearchanges are and how sticky the tyres as it is torque that kills the boxes. I have used both ATF and fully syn 75W and the gearboxes all eventually died so much so they have been declared consumables for years. I would budget a box a season - that how long they lasted me while sprinting - but have a spare handy. Usually they would get baulky and noisy and the synchro would go but I have snapped shafts with the last two LT77s I had. Mind you I stripped the teeth on an uprated T5... ATF does seem to give the best change and I have broken boxes with 75W. Whatever you use, I would change it frequently. Try them both and see how you get on.

BTW I am now using fully syn 75W but that is in a custom T5 box.

[TVRleigh_BBWR]

shpub said:

With only 230-240 real bhp, it is not that important as it isn't really that big a stress.

The big factors will be how violent the gearchanges are and how sticky the tyres as it is torque that kills the boxes. I have used both ATF and fully syn 75W and the gearboxes all eventually died so much so they have been declared consumables for years. I would budget a box a season - that how long they lasted me while sprinting - but have a spare handy. Usually they would get baulky and noisy and the synchro would go but I have snapped shafts with the last two LT77s I had. Mind you I stripped the teeth on an uprated T5... ATF does seem to give the best change and I have broken boxes with 75W. Whatever you use, I would change it frequently. Try them both and see how you get on.

BTW I am now using fully syn 75W but that is in a custom T5 box.

Thanks Steve,
Well I'm going to use full slicks, I'll try and be gental on the changes but depends on what going on in the heat of the moment.

I do understand they are going to be consumable, and I will be useing a T5 next year. but wanted to get the car finished, so did not want extra complications.
Next year I'll have more time, so will be able play with fitting a T5.
Also planning on fitting a supercharger also.

If I get time may bring it to a sprint. won't be till near the end of the season though.

Leigh

[mikeb]

Rev, YHM.

MikeyB

[shpub]

A T5 will cost around £2000 to fit (new prop, bellhousing, clutch slave and possibly new clutch along with mounts, remote and the cost of the gearbox) and the Griff/Chimaera setup is not the right fit for the wedge. Unless the T5 is a CTS/Quaife jobbie, it is not much better than an upgraded LT77. The CTS Quaife unit is around another £2000 so it starts to get very expensive.

[rev-erend]

mikeb said:

Rev, YHM.

MikeyB

Thanks Mike.

How come you are still Wedgepages..

[TVRleigh_BBWR]

shpub said:

A T5 will cost around £2000 to fit (new prop, bellhousing, clutch slave and possibly new clutch along with mounts, remote and the cost of the gearbox) and the Griff/Chimaera setup is not the right fit for the wedge. Unless the T5 is a CTS/Quaife jobbie, it is not much better than an upgraded LT77. The CTS Quaife unit is around another £2000 so it starts to get very expensive.

Well I've spent 13k so far on the car.
Also the car has custom Engine and Gearbox mounts, so they can be easily changed.

I know it's not a simple job of just dumping it in, hence leaving it till next year.

[Henry Harris]

Thanks for all the comments so far. Chasing a number of contacts. No luck so far. Let you know.

Edited by Henry Harris on Sunday 27th April 11:48

Edited by Henry Harris on Sunday 27th April 11:48

[mikeb]

rev-erend said:

mikeb said:

Rev, YHM.

MikeyB

Thanks Mike.

How come you are still Wedgepages..

...Better than Griefpages I suppose ;-)

Still, Wyn seems to like 'em.

MikeyB

[pwd95]

I'm really trying not to honest....
Mike we'll have to meet up for a blast, I'll give you a go.

[mikeb]

Tried changing the air filter yet? - another fine bit of design. Noticed that you had the roof on whilst on the SWPH run the other day, thats 'cos they don't fit in the boot! or given a passenger a lift on an extended run without their legs cramping up? or tried scrapping off the 0.00001mm thick rust protection on the chassis?.

....Still, the glovebox catch is good. ;-)

Some things just need to stay on the bedroom wall....IMHO of course.

MikeyB

[Henry Harris]

The box is back in place now. The issue I had was wishing to replace some of the gears that appear to have been TVR specials. I have left them as is for now.

Thanks for your interest.

Edited by Henry Harris on Monday 5th May 09:58