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Discussion Starter · #1 ·
Anybody have any experience in doing these conversions? Which is really better, a Getrag 240 or a ZF gearbox? Any comments?
 

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The ZF is much, much stronger than a Getrag 240. It does not shift quite as smoothly but with synthetic gear oil it is not bad at all. Also the gear ratios (3.85-1.00 box) improve the vehicle acceleration drastically, the Getrag ratios are horrible for a tuned engine. The only real 'down' sides are the extra weight, and the lack of overdrive for highway travel.

Bob
 

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1971 GT
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This begs the question - which ZF tranny will fit and how difficult is the installation?
 

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ZF Tranny install.

The ZF gear box was used on several European models, Ford, Opel, BMW, etc. The key is the bell housing. I believe that it will fit the Opel bell housing, but I could be wrong. We need Bob to ring in on this one.
 

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Lateral Thinking

High priced gearboxes from far away ........ Try someting cheap and local!
Has anyone had a good look at adapting the Toyota Celica RWD five-speed box? The junk yards must be full of them and they will handle small V8s! I had one behind a 3 litre Holden six-cylinder and it was superb.
 

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That would be great if a domestic, or commonly imported, strong, cheap, smooth 5 speed transmission would work or fit easily with an adapter plate.
 

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CDN OpelNut said:
This begs the question - which ZF tranny will fit and how difficult is the installation?
There were four Opel-specific ZF's made (direct bolt-in). Two were production-based and were optional on Kadett C GT/E's (3.85/2.40/1.76/1.26/1.00 ratios or 2.99/1.76/1.35/1.00/.87 ratios), the others were motorsports-option units only and were very close ratio units (2.85/1.80/1.36/1.14/1.00 ratios or 2.30/1.80/1.36/1.14/1.00 ratios). All are relatively rare, the racing units are very rare, and they're VERY pricey to get any parts for. You must have the bellhousing for the CIH or it won't fit, even if you have a ZF from another model vehicle.

Installation is easy, the shifter location is stock, the driveshaft from an automatic is a direct fit, and the reverse switch is adirect plug-in. The tranny mount used is the same as a GT....the only modification needed is the mount crossmember needs a bit of reworking to fit.

HTH,
Bob
 

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what would be needed to install a getrag 240 5-speed. can you bolt it right on or does it need some modification, how many and how hard?
cheers
tom
 

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boomerang opeler
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tom if you do a search you will find lots of posts on doing a change to a 5 speed box
 

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Discussion Starter · #12 ·
Gearbox

I got the ZF gearbox for Manta. Ratios are 3.85/2.40/1.76/1.26/1.00/R3.64. Came with bell housing, shifter and mounts.
 

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Discussion Starter · #13 ·
Attaching photos of the ZF gearbox before I fitted it to the car. Put it on now and Bob is right, shifting is not so smooth since it has a very mechanical feel. Ratios are great though, with the 3.44 rear end, it runs great.

There is a little gear whine that comes with all ZF S5-18/3 gearbozes but found out it goes away with synthetic gear oil.
 

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Mounting the 5 - speed

Just spent a frustrating evening trying to test-fit my new Getrag to the motor to see how much grinding of the inside of the bellhousing is needed.

How much pressure is needed to slide the new tranny on? I cannot get it even far enough on to engage the splines. The bearing in the crank is OK and accepts the clutch centering tool easily.

What is the best one-man method for this job?

Right now, the only thing I can think to do is use the bellhousing to block bolts to pull the tranny on. Is it acceptable to force it on this way?
 

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Old Opeler
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Treat it like a Young Virgin !!

What is the best one-man method for this job?

Right now, the only thing I can think to do is use the bellhousing to block bolts to pull the tranny on. Is it acceptable to force it on this way?
If the gearbox does not slide into place - right up till the bellhousing contacts the block - something is WRONG

Check that the pilot bearing fits on to the spigot; that the pilot bearing is correctly installed; that the spline slides smoothly through the clutch and that everything is correctly in-line.

Be GENTLE !!

Forcing it will bend the clutch disc and/or break the bellhousing - NEVER pull the gearbox on by using bolts to wind it in.

Sometimes a couple of studs, or bolts with the heads cut off, can help guide the bellhousing up to the block.
 

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Yeah there is something wrong; most likely it is the pilot bearing alignment. You have to be precise when using the pilot alignment tool; often folks will put it in, and then tighten the clutch into place, but not pay attention to the fact that the alignment toll has sagged slightly and allowed the alignment to be just a small bit away from perfect. You have to keep the alignemnt tool centered as perfectly as you can while tightening the clutch cover.

Re-align and retighten the clutch as precisely as you can and try again.

Good luck!
Mark B.
 

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Corey;
Check this out:
http://tekenaar.opelgt.com/getrag/images/getrag_s10_grind.jpg
If that doesn't help, then get longer bolts, but, use them to just hold to the trans (make sure the gap is even all around, prop up the trans if you have too) then, spin the crank back and forth (not trying to make a complete revolution, just a 1/8th turn) to mark on the inside of the bell housing where the pressure plate is contacting and start slowly clearancing the bell housing.
 

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Tranny is on.

I'm not sure what the problem was the first time I tried to mount the tranny, but I dissassembled the clutch, tried the disc on the spline, mounted the tranny without the clutch in place and every thing mated OK.

I re-assembled the clutch and tried again and managed to get it together. No interference from the S-10 clutch on the bellhousing either. The clutch cover had to be pulled quite a bit to the flywheel, but I'm assuming that normal enough. Everything spins nicely. The arm pivot bolt that I made from the mercedes lug has lots of room for future adjustment.

next question

The Getrag came with a blue speedo gear for use with W-1062 speedos. My speedo is KPH and is marked 557. (It's always been 20 KPH out with the 4-spd)

Obviously, I won't use the blue gear, but what is the gear that comes in the Getrag for, and will I have to change it?
 

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