Shattered Mt75 Gearbox

[bullfist]

Hi,

My (2004) Super-spec gearbox has shattered its bell-housing (pictures at www.sernat.net/gearbox). 3D transmissions in Reading took it saying they could weld it - before actually seeing it. But the crack is too big, the weld will distort the bell-housing. Se we're looking for a replacement housing, but we cannot identify the donor car. The closest I've got is that it came from a 2.9 V6 Sierra (2WD) and may be a LHD version. Any help in obtaining a replacement case or identifying the type will be greatly appreciated.

Thanks,

-Steve

[agent_zed]

looks a bit like the one on my dads j-reg transit. not sure if that helps.

i'll have a closer look at it tomorrow when its light.

 

hth

[ibrooks]

2wd Sierra Cosworths use a T5, not an MT75. The bell-housing looks like the V6 pattern so you'll struggle to find a 2wd replacement in this country - there are very few 2wd V6 MT75 boxes in the UK (apparently they are quite common on the continent).

 

They are quite sought after by people who want to put a Scorpio Cosworth engine in a Sierra but don't want to go 4x4.

 

It's possible to make up a hybrid box using the front half of the casing from a V6 4x4 Sierra and the rear half from a 4-pot 2wd but you need to mix and match the guts too in order to use the longer V6 input shaft.

 

I've also heard tell of Scorpio diesel gearboxes being suitable as they also have the longer input shaft but I don't know if you still need to use the front half of the casing from a 4x4 box. This is also quite popular on Scorpio Cosworth transplants as the Cosworth V6 doesn't spin to particularly high revs in standard form and the Diesel box got a longer 5th gear which gives more relaxed cruising and a silly top speed.

 

Of course if the guts of your box are OK then you should just be able to get a 4x4 V6 box and use it's front casing.

 

Iain

[Grim]

is it possible that the bell housing failed due to the known misalignment of rover superspec mt75 setups? If so, that needs addressing before gearbox replacement.

[Longboarder]

MT75 to rover engine is an abortion of a match. Someone does make bellhousings to allow this engine to be properly mated to the type 9 box.(Saw an article in PPC a while back) Would need a new prop and some clutch bits but that's an alternative way to go which would be much more satisfying from the engineering point of view. IMO

 

Nigel

[Snapperpaul]

Rusty had to have his rebuilt, GBS quoted 600 for a box.

They have the soars that Richard amassed.

So the MT75 used on the Superspecs was a left hand drive V6 version with bell housing cut to take Rover starter

[stevedohc2b]

Could it not be tig welded as a repair?

 

stephen

[bullfist]

Thanks for your replies. 3D transmissions in Reading have the box and they say they cannot weld it (and they're meant to be quite good). First Motion transmissions has seen the photos too and agrees that it is a bit too far gone for welding. MT75s are quite common in Transits - but the bell-housing is different. Can someone point me to the thread about the MT75 super-spec mis-alignment as that may explain why it failed. I had a failed prop-shaft but drove it 5 miles home slowly with the gearbox shaking very excessively - so I put the failure down to the prop-shaft failure weakening the gearbox.

[harvs]

I had a failed prop-shaft

wow - What happened to the prop shaft?

[Guest QuadraDave]

Hi can anyone tell me how many gearbox clutch or propshaft failures there has been on the rover engined super specs that are completed and on the road thanks Dave D

[Guest mower man]

IMHO too many don't know a lot about the setup but probs seem to pop up with regularity !Was the prop failure joint or tube failure ? seem to remember horror stories about twisted props some time ago regards mower man

[bullfist]

wow - What happened to the prop shaft?

So I had just had it SVA'd and got my new reg. plates and bolted them on after work. Took daughter1 for a spin round the block - wow this is great. Took daughter 2 for a spin round the block. Offered wifey a spin but she refused, so took daughter 2 for a race up the ring-road. Moved into fast lane as car approached up the slip road when BANG! Gear-level severely vibrated out of my hand. Pulled over and had a look underneath (thought something had dropped) but looked OK. Moved forward slowly in 1st gear - ok. Into 2nd and 3rd but any higher and the car wasn't having it. So drove it home in 3rd gear (very noisy - and we certainly attracted attention to ourselves). Covers off at home, and the spider in the front prop-shaft UJ had lost its bearings. So the UJ was engaging to get me home but was banging about in the transmission tunnel.

And I then had just eight days to get it repaired so that I could take my daughter to the prom. Just managed it - got the new spider back an hour before the prom. Cursed and swore to get the car running again, and a quick drive round the block - all OK - had ten minutes spare! But we certainly made an entrance (and I drove very carefully).

(Sorry about the rambling...)

[Snapperpaul]

One of my mates had a prop failure on a Superspec fitted with a pinto, prop spun up like a stick of Liqorish then broke, the prop tube was way to thin and looked like exhaust tubing.

 

Rusty's box had gear selector problems which may have led to the failure, it was to say the least a bad bodge and had plated tube tacked to steel which failed, he took a standard lever and it's associated bracketry and lengthened that.

[harvs]

Hi Bullfist

 

Congratulations on the SVA/IVA

 

Glad you were all OK. Bet your daughter enjoyed her prom entrance!

 

I'm replacing my prop shaft at the minute as I think it's been causing vibrations at high (ish) speeds. Soon find out, and will have more confidence that it's not going to fall apart a few inches from my legs....

[bullfist]

I'm replacing my prop shaft at the minute as I think it's been causing vibrations at high (ish) speeds. Soon find out, and will have more confidence that it's not going to fall apart a few inches from my legs....

 

I was quite impressed when mine failed a few miles from home - I thought it would bash its way through the transmission tunnel. But it just rumbled and banged about as I drove the few miles home at 30mph. And I was doing 70(ish) when it broke.

 

Yes, daughter was impressed - we certainly made an entrance (she was talk of the evening). When I get the hang of this forum will post photos, and story of getting through the IVA at Southampton.

 

Latest update on casing. 3D transmissions returned it to the local garage, where they think they might be able to bolt it to a steel plate before welding - they're asking around. Otherwise I will build a subframe to hold it together over Xmas.