G50 Install Issues...

[Corsair613]

With the help of two friends, I got the LS7 installed yesterday. It looks really good nestled in there. The only problem at all was due to the swirl pot connection through the reducer to the engine's water outlet. It just wouldn't make the necessary turns no matter how we trimmed the hoses. Another solution (flexible line?) will have to be found.

The transaxle, though, was a different story. Despite using a clutch alignment tool to install the flywheel/clutch assembly, the gearbox simply won't slide home. The splines are definitely engaged, so that's not it. The gear selector fork is not obstructing things (it's just about to slide between the gearbox bearing mounts), so that's not it. I think the issue is that the nose of the output shaft isn't entering the crank bearing.

At this point, I'm pretty much at a loss as to what else to do or try. Any suggestions that I can attempt before being gone all next week? I'd really hate to have this hanging over my head all week.

Ken

[Corsair613]

Here's a idea:

Is it possible that my clutch alignment tool (heavy plastic) deflected under the weight of the pressure plate such that, while tightening those nine bolts, the concentricity between splines and crank bearing was slightly spoiled? That would account for the alignment tool being able to slide in and out with no trouble, while the steel clutch shaft is passing the splines but not entering the bearing.

Thoughts?

Ken

[Storer]

Corsair613 said:

With the help of two friends, I got the LS7 installed yesterday. It looks really good nestled in there. The only problem at all was due to the swirl pot connection through the reducer to the engine's water outlet. It just wouldn't make the necessary turns no matter how we trimmed the hoses. Another solution (flexible line?) will have to be found.

The transaxle, though, was a different story. Despite using a clutch alignment tool to install the flywheel/clutch assembly, the gearbox simply won't slide home. The splines are definitely engaged, so that's not it. The gear selector fork is not obstructing things (it's just about to slide between the gearbox bearing mounts), so that's not it. I think the issue is that the nose of the output shaft isn't entering the crank bearing.

At this point, I'm pretty much at a loss as to what else to do or try. Any suggestions that I can attempt before being gone all next week? I'd really hate to have this hanging over my head all week.

Ken

Ken

Time to do some measurements (you may have already).
Two obvious ones first.
Gearbox input shaft diameter
Crank bearing diameter.
Then the distance that the gearbox input shaft protrudes forward of the housing and then the distance from the adaptor plate to the forward face of the crank bearing.

Assuming they are compatible.
Getting the angle of the box to the engine correct is not easy but obviously essential.
Also measure the distance from the thrust bearing to the clutch plate.
Last thought. Are you using the 'rubber band' support method for the clutch fork? If not this could be your problem.

Pictures may help us help you. Inside the bell housing especially.

Good luck

Paul

[Storer]

Corsair613 said:

Here's a idea:

Is it possible that my clutch alignment tool (heavy plastic) deflected under the weight of the pressure plate such that, while tightening those nine bolts, the concentricity between splines and crank bearing was slightly spoiled? That would account for the alignment tool being able to slide in and out with no trouble, while the steel clutch shaft is passing the splines but not entering the bearing.

Thoughts?

Ken

Could be a possibility Ken. I made mine on the lathe from aluminium.

Paul

[Storer]

Another thought.
You will need to jack the rear of the engine up a little to help with box fitment.

Everything else looks the same as mine so should all fit.


Paul

[Steve_D]

You could try taking the clutch off again and offer up the box alone. That way you can assure yourself that the shaft is engaging the spigot bearing and that all the lengths and diameters are correct.

If that works then it can only be the clutch to spigot alignment or the clutch release mechanism preventing it from going home.

Steve

[Corsair613]

Thanks, guys - that all sounds like good advice. I'll pull the box for measurements and photos tomorrow.

Ken

[bluesatin]

Which gearbox? Have you had the inside of the bell machined?

[Corsair613]

bluesatin said:

Which gearbox? Have you had the inside of the bell machined?

It's a G50-03 (with the uprated 5th gear), obtained from the factory.

I haven't had anything done to it at all. As a factory-prepared box, it ought to install directly with no further machining required, right?

Ken

[mt308]

Corsair613 said:

bluesatin said:

Which gearbox? Have you had the inside of the bell machined?

It's a G50-03 (with the uprated 5th gear), obtained from the factory.

I haven't had anything done to it at all. As a factory-prepared box, it ought to install directly with no further machining required, right?

Ken

My factory supplied box (G50-20) slotted straight on, I didn't need to do anything.

Good luck!
Mark

[Storer]

Ken

Another thought.
You are not trying to install the transmission with the clutch fork pivot pin in situ are you?
It has to be fitted after the box is bolted to the engine.


Paul

[Corsair613]

Storer said:

Ken

Another thought.
You are not trying to install the transmission with the clutch fork pivot pin in situ are you?
It has to be fitted after the box is bolted to the engine.


Paul

Hey Paul,

That's a good thought, but no.

We're about to have lunch and then attack the box this afternoon. I'll run through the various measurements, take photos, etc. I'm also going to remove the clutch and see if the box will seat properly without it. If so, that'll narrow things down considerably. Also, not having the clutch in place will help with visualizing the proper alignment between engine and gearbox. Then, I'll just replace the clutch and slide the box back on. It's a good theory, anyway…

Ken

[ROWDYRENAULT]

There is a small chance that you may have the same problem that I encountered. When installing the G50-03 onto my LS motor the transmission would slide nicely into place until it was about .120 from home. After much head scratching turns out that certain LS rear main seal support plates where manufactured with an extra .120 worth of materiel towards the back of the motor. I contacted Kennedy Engineering who built the adapter plate and they concurred that they had seen this problem before and offered to machine the piece to fix the problem. We did it here, problem solved. This was a very limited number of these rear main seal plates manufactured by one of G.Ms suppliers and the thickness does not bother G.M.s installs so no reason for them to be concerned. Hope you find the issue, Lee

[Corsair613]

After a long afternoon of wrestling with the gearbox, I'm fairly convinced that the problem is an alignment issue caused by my clutch alignment tool allowing the weight of the pressure plate assembly to shift things every so slightly as it was tightened down - just enough to prevent the gearbox shaft from entering the crank bearing.

I have a second bearing on hand (previously measured as being identical to the one installed in the crank by AS) and it fits perfectly on the end of the gearbox shaft, so it's not a sizing incompatibility.

I'm fairly certain now that the solution will be to remove and reinstall the clutch while making a greater effort to avoid any deflection. I will say that I was surprised at just how close the entire flywheel and clutch assembly sits to the inner face of the bell housing. So close that the slight misalignment resulted in the starter ring scratching the paint inside the bell housing in a few spots.

I might not get this done tomorrow (I've got a local classic car show to attend), but I'll be less worried about it during my week away. Thanks, all, for the great advice. I'll post a note here to confirm that it's all set once I finally get the gearbox installed.

Ken

[MarkWebb]

I bought a supposed good clutch alignment tool and had the same issue until I lined it up perfectly by eye. Then she slipped straight on.

[Corsair613]

MarkWebb said:

I bought a supposed good clutch alignment tool and had the same issue until I lined it up perfectly by eye. Then she slipped straight on.

That's the plan. I get home on Friday evening, so Saturday morning I'll be out in the garage doing just that. Fingers crossed...

Ken

[Corsair613]

I'm still out of town, but a few friends stopped by my place thinking they'd get things sorted for me in my absence. That would've been really nice, but it wasn't to be.

Turns out that the guide tube on my G50-03's input shaft is both too long and too thick to allow the transaxle to seat properly. A call to Ultima revealed that they'd installed the wrong guide tube and a different part needs to be swapped in. They're sending me the new guide tube via FedEx, so it should arrive on Monday.

My friends tell me that the two screws holding the incorrect guide tube in place are hellaciously tight. The factory mentioned that they might have to be drilled out, so that's probably on schedule for the weekend.

More to come as the adventure continues...

Ken

[Steve_D]

Drilling would be a last ditch route for me.
Try an impact screwdriver. This will be better than an impact gun as it applies a force onto the end of the screw at the same time as trying to turn it.

Steve

[Corsair613]

Steve_D said:

Drilling would be a last ditch route for me.
Try an impact screwdriver. This will be better than an impact gun as it applies a force onto the end of the screw at the same time as trying to turn it.

Steve

Yep, I'm definitely planning to try the impact driver first. Hopefully, that'll work.

This whole issue is evidently a known thing, with Porsche having changed from 34mm to 32mm guide tubes in the late '80s. I find it fairly remarkable that Ultima didn't confirm the matching fit of the gearbox and clutch it supplied with my kit.

Ken

[Corsair613]

OK, the impact driver didn't work at all, so I resorted to drilling out the screws as suggested by the factory.

The good news is that I got the screw heads drilled and the guide tube removed. The bad news is that there wasn't any of the screw shank left to grip. My "easy out" screw removers didn't work at all, so I drilled through one with a smaller drill and successfully removed it. The catch is that I smelled gear oil when I was done. So…

Are the guide tube screw holes meant to be through holes into the case or are they blind holes? Did I drill too far and, if so, what are the consequences? Needless to say, I'm not doing anything to the other one without further guidance.

Also, what's the correct thread pitch for these holes? M5? I'm going to need to clean the threads in the drilled hole(s)…

Thanks, all.

Ken