transmision explodes during trackday :-( NEED HELP

petke

Registered User
Hello members,

After enjoing my supercoupe for a few months now, and a recent complete suspension link overhaul and geometry, I took out my Bird for a local track-day.

Few laps went well, so I tried to warm my tires with burnout... when applying a rapid declutch to create wheelspin, I heard a snap and the wheels stayed still. Three metal (aluminium) bits were left on the tarmac. It seems the rear end of my 5speed gave up.

Since I opperate my supercoupe in europe, Im not swamped with parts and spares, nor advice. Thank god I have a spare car without engine block, but with everithing else on it. I will attempt to make a working trans out of the one I have sitting in the spare car, but its been sitting there for years. I also have the official workshop manual from ford to help me.

I need help in sourcing the seals and bearings to refurbish the old 5 speed. PLEASE HELP!!!

As one of the few european Supercoupe owners Im keen on keeping my lovely musclecar alive, so any advice will be greatly appreciated.

Best regards,

Peter
 
It sounds like the gears could have broken but I'm not sure what the aluminum could be from. Check your axles, though. You may have broken one of them instead. It is much more common. They break at the hub and should be easy to check. Shipping from here to Europe could be a problem but both Supercoupe Performance and Spinningwheels SC who are both on this website carry the parts you'll need rebuild the differential.
 
replacement in progress

So I already took out the spare transmission, looks fine. Done some work on the broken car, removed exhaust, disconnected the driveshaft, so now just have to take it out and move the clutch to the spare trans.

The transmission failure is caused by the disintegration of the tail of the transmission (bottom broke off) and the splined shaft inside the yoke broken in a weird spiral pattern (will attach photos soon).

Has anyone had the same failure? Any ideas for probable cause apart from the quick declutch, which was the last straw that broke tha camels back?

Question: Can I replace the bolts connecting the driveshaft with the differential wit bolts, which have better access? It was a pain to remove the bolts , because the u-joints were in the way.
 
So, the M5R2 5 speed is what broke. If the tail housing is broken, there have been a few of those. I have a spare tail housing but you may have more damage than that. Let's see your photos.
 
That is a very common failure and because of that, parts are hard to come by. Many a working 5spd transmission I've disassembled was already cracked, just not broken yet (and that's not counting the many, many broken ones I have had experience with). The cause is just about 100% due to wheel hop, and for that reason great care must be taken if/when driving the car at the track specifically, but street use can be damaging as well.

The solution for this problem is that absolute care must be taken NOT to allow the wheels to hop under power to have the new transmission and/or axles hold up. I suggest that the ONLY tire for someone like yourself to use at the track is a Mickey Thompson ET Street - NON radial - tire. Best example is the 26 x 10.50 x 16. These tires will save your driveline. For this reason I do not recommend that anyone take any 5spd SC to the drag strip without first purchasing the above mentioned tires.
 
I've got a spare output shaft and tail housing but getting them to you could be expensive. Plus, if there is anything else damaged you'll need those parts, too. It would almost be better to find a complete transmission and use this one for spare parts. Again, shipping could be expensive. I do have a spare '94 tranny available.
 
spare trans

Thanks guys for the quick reply. As I mentioned in the previous post, im lucky enough to have a spare transmission from the spare car (came with the rolling one, is for spares less engine block due to engine failure). So Im set for now. Ill give it new oil (ATF DEXRON-IID), new clutch slave cylinder and bearing (since its just before failure) and im in process if chasing seals front and back to prevent possible leaks due to aged seals on the spare.

For the future, how much does a M5R2 go for?

Do you know the part numbers of the seals needed to prevent leaks from a global brand, like SKF (so I get them localy)?

Should I also change the driveshaft as well? It could have been damaged (the yoke part), but again the old shaft is matched to the old diff... so Im a bit hessitant.

Thanks for replies again.

Ive been in a hurry to fix it to take part in a local US car-meet. But Im not gona have it put together with a ~~~~e slave cylinder..., so Ill just be a spectator this weekend. :-/
 
I suggest that the ONLY tire for someone like yourself to use at the track is a Mickey Thompson ET Street - NON radial - tire. Best example is the 26 x 10.50 x 16. These tires will save your drive-line. For this reason I do not recommend that anyone take any 5spd SC to the drag strip without first purchasing the above mentioned tires.

when the man speaks, we listen :D
 
wheelhop

That is a very common failure and because of that, parts are hard to come by. Many a working 5spd transmission I've disassembled was already cracked, just not broken yet (and that's not counting the many, many broken ones I have had experience with). The cause is just about 100% due to wheel hop, and for that reason great care must be taken if/when driving the car at the track specifically, but street use can be damaging as well.

The solution for this problem is that absolute care must be taken NOT to allow the wheels to hop under power to have the new transmission and/or axles hold up. I suggest that the ONLY tire for someone like yourself to use at the track is a Mickey Thompson ET Street - NON radial - tire. Best example is the 26 x 10.50 x 16. These tires will save your driveline. For this reason I do not recommend that anyone take any 5spd SC to the drag strip without first purchasing the above mentioned tires.

How do these tires exactly prevent wheelhop. Is it by increased traction? do they damp better? Im just curious. Ive had a previous thread, where I mentioned I have a problem registering different tire sizes. So I think Im stuck with a narrow choice of tires.

Are there other measures to prevent wheelhop? Shocks maybe?

My mechanic told me my shock absorbers are leaked out, but they still react well to ARC turning on... So i guess there still must be some oil :-D
 
you get rid of wheel hop by taking the rear subframe down and grinding off the center notches on the mounts that prevent the subframe bushings from loading
 
I tend to have very little wheel hop with wider tires, however, even these will hop on occassion. I always do burnouts with wet tires rather than dry and if the wheels do start to hop I push in the clutch and get off the gas immediately. Your driveshaft should be Ok but give it a good inspection first. Some of the guys have put airbags in the springs and others have replaced the rubber subframe bushings with metal ones. I just try to be careful.
 
XR7 Dave was selling complete bushing kits made of a stronger plastic material, which removed the sloppy and worn out rubber from all the rear suspension points, and also deleted the toe link. That set-up is supposed to do a great job removing wheel hop. I have a set, just have not gotten around to installing them :rolleyes: Seeing that Dave chimed in here and did not mention the bushings, he may not have/plan to make any more?

I believe another member here and on TCCoA took over DLF's operation when he passed away (RIP). I THINK he goes by Jaybob ? (have a set of THOSE too, again never got to installing :rolleyes:)

Adam
 
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