Where to find help when you want to change major units on your CF - engine, transmission, brakes etc. - or upgrade earlier models to later specifications.
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Gearbox dilemma

Post by BigRedBusBar Contact BigRedBusBar » Subscribing Member » Mon Jun 11, 2018 1:45 pm
Joined: Wed Mar 21, 2018 9:27 pm
Posts: 7
Hi all,

We acquired a CF at the start of the year, which had gearbox issues, so we purchased a replacement 'box on ebay...
After months of waiting for the gearbox to be recon'ed using some parts from the eBay one and others from our original 'box, our garage how now unfortunately admitted defeat and said it isn't going to be possible to get it running correctly and it's "noisy as hell in neutral" no matter what he does apparently.

I'm hoping someone might be able to give us some inspiration/advice!
Wondering whether we should a) look for another Opel 'box, b) look into adapting a similar 'box (mechanic advises he could adapt a Vauxhall 101 to fit?) or c) re-engine with a Transit engine and 'box?

Thanks very much in advance for any advice you might be able to give!

Re: Gearbox dilemma

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Post by Phil Bradshaw » Club admin » Mon Jun 11, 2018 5:13 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3579
Which engine is fitted?
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Gearbox dilemma

Post by BigRedBusBar Contact BigRedBusBar » Subscribing Member » Tue Jun 12, 2018 11:21 am
Joined: Wed Mar 21, 2018 9:27 pm
Posts: 7
Hi Phil,
It's a 2.1 Opel diesel

Re: Gearbox dilemma

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Post by Phil Bradshaw » Club admin » Tue Jun 12, 2018 11:07 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3579
In brief -

Opel 4-speed transmission is more scarce than the Vauxhall transmission this side of the Channel; there is one on eBay at present but it's anyone's guess what it's like inside.

For a Vauxhall transmission you'll need the clutch housing for GM diesel to go with it. First find a transmission though, or enough donors to build one serviceable unit. Vauxhall 101 (FC Victor) is a bit too old and won't have the CF gear shift turret (or lugs for the upper bolts) or the correct striking levers cross shaft.

FD/FE Victor/Ventora and HC Magnum transmissions have common internal components for mending CF gear train faults but for a 21D a CF unit with 15-tooth input shaft pinion would be best - car transmissions can have 20- or 21-tooth pinions which will need lots of clutch slip to get the van moving without stalling the engine.

ZF transmission with GM/Opel clutch housing should bolt straight on but you'll need the gear shift lever and speedometer cable for ZF. For short wheelbase models the rear mounting cross member needs spacer brackets at both ends to drop the mounting position about 1 inch for the transmission to clear the cab floor and box section stiffener to the rear of the gear shift aperture.

4-speed or 5-speed ZF should fit: juggle cross member and mounting fore and aft positions to suit. 5-speed for diesel usually is 1:1 5th speed. Overdrive 5th (0.8:1) for Opel CIH petrol engines may not be a good idea on a 21D if the van is laden much of the time - 5th may only be usable downhill with a following gale. Diesel 5-speed with 1:1 5th provides a low ratio 1st gear ('crawler' gear) instead.

For Vauxhall or ZF a propellor shaft (front end at least) will be needed to match the transmission for shaft length and sleeve yoke (Vauxhall splines) or ZF flange yoke.

Ford type 9 transmission with side mounted gear shift (Transit) can be fitted using an adaptor plate made to fit the front of the type 9 and rear face of the clutch housing; type 9 input shaft will need a Ford clutch centre plate to fit the splines. Rear mounting cross member will need fettling to fit a support frame to bolt the mounting to. Speedometer cable will need the Ford end for the fork clamp on the transmission and the propellor shaft will need shortening with a Ford front yoke fitted.

Engine swap is feasible but that's another story entirely...

EDIT

If the 21D has the 4-bolt clutch (Opel) then a flywheel for 6-bolt (Borg & Beck) clutch would make things easier for matching centre plate to transmission input shaft splines.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Gearbox dilemma

Post by BigRedBusBar Contact BigRedBusBar » Subscribing Member » Wed Jun 13, 2018 12:08 pm
Joined: Wed Mar 21, 2018 9:27 pm
Posts: 7
Thanks very much Phil! Will pass this info onto our mechanic and report back...

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