getrag 265 speedo drive problem

[jivili]

Hi.

Just been driving the car prior to taking for its first mot after rebuild.
I have a series 3 with a getrag 265 from an newer xj40 fitted.
All is fine but the speedo has stopped working.
I suspected the angled drive had failed but when I have stripped it down the angled drive and speedo are still ok and it seems that the mechanical drive that sits in the side of the gearbox is not working.
I have pulled this out and the actual drive unit appears fine.
When I reinsert into the side of the gearbox it doesn't appear to mesh into anything and I can spin the angled drive by hand.
Does anyone know what the problem could be as I know very little about the internals of the gearbox and really not looking forward to the possibility that I have to remove the engine and gearbox from the car to rectify this

Many thanks
Dean

[PeterCrespin]

From memory the helical worm drive gear on mine was held by clamping alone, no key. So if the tailshaft nut came fractionally loose you might find the gear spininning on the shaft instead of driving. I had speedo drive trouble initially with my secondhand Getrag, but from memory it was a brass driven gear that wore out, not the steel driving gear.

MC Wilkinson used to do the parts, at least the short 265 gearboxes they sold, rather than your long one which is different in having a long tailhousing and sliding rear yoke IIRC.

[jivili]

Peter

thanks for that.
I have taken a couple of photos of the speedo drive and it appears to me to be in good condition.
I cannot understand why when fully inserted the geared end does not mesh in with a drive in the gearbox (a bit like a distributor).
I have tried it with gearbox in neutral and in gear but no difference and it can be rotated with my fingers which would indicate to me an internal gearbox issue
I was just hoping that someone who knows how they are supposed to work could help me

Dean

[Heuer]

This may or may not be helpful but I have Borg Warner T5 and had a similar problem. Turned out the speedo drive worm had moved because a clip had failed. You should be able to use a finger or screwdriver to feel for the worm to see if it has moved. In my case the failure of a tiny clip allowed the worm to move backwards on the main shaft but as this also held 5th gear in place it meant the car was un-drivable. You need to find a schematic of the Getrag or speak to someone who understands them but in the meantime do not drive it as failure will be catastrophic for the gear box. Let us know what you find out.

[MLBS3V12]

Hi,
not sure if it is the right reason.
I will also use a getrag 265. It comes from a BMW E24. In other words it is a short tail one with an output flange.
This output flange keeps the speedo drive pinion tighten with the nut and the first ball bearing close from the outer seal.
If the nut is not tighten enough, the speedo pinion can be not drive anymore.
I do not know how it is managed into the long tail model.
Hope this make sense.
I've able to find the gearbox drawing for the BMW Getrag 265 but not for the "opel" or "Jag" one.

Sorry for my English, it is clearer in french in my mind. :D

[42south]

Hi
I have the long tail Getrag 265 on my S3, and have just had the same problem.
The speedo drive cog is held onto the main gearbox shaft by a metal spring clip.
I dislodged/broke mine when reinserting the drive shaft into the rear of the gearbox.
You can get spares from a guy on ebay, he is in Germany. If you search on Ebay UK for Opel Getrag spares you will find his ads, If you ask questions he can use English.

[42south]

Hi again
Some further thoughts on replacing the clip if this is your problem.
You can supposedly replace the clip in situ through the speedo drive opening, I have a description relating to the Opel tail that is on mine, yours should be similar. I can send to you, pm me.
If you decided to remove the gearbox, it is better to drop the diff and pull the driveshaft out that way.
However you may still find that the gearbox does not come back far enough to remove it upwards through the tunnel due to a reinforcing member blocking the tail from moving upwards.
You will need to make a tunnel modification, by cutting a piece out. This is not a big deal as it can be reattached by taking it to your local friendly panelbeater and getting a lip on this piece then using a few rivenuts to attach it. The end result looks pretty jaguar, and is hidden under the carpets.
I have a couple of photos if you need them.
All the above is a much better option than pulling the engine and gearbox out again.

[jivili]

Mark

I have tried to pm you but it doesn't seem to want to work for some reason
Can you send the info you have to dean.revill@jivili.com please.
I would like to attempt to replace the clip in situ if at all possible

[jivili]

Have spoken with a very knowledgeable guy today from Allgears at Worksop who has pretty much confirmed what Mark has said about the clip coming off that holds the drive gear for the speedo.
Apparently they are prone to it.
He has told me that this is not a 'in-situ' fix and that the gearbox needs breaking down to fix it.
He did say however that it is no problem to use the gearbox as the clip can't do any damage.
I have to decide now whether to take the gearbox out and get it fixed properly or make use of a gps speedo and live with it.
I suspect that the angled drive was the cause of my grief as it seems to have a tight spot when I turn it.
He says that the clip that holds the getrag speedo drive cog on the drive shaft is always the weakest link in the setup and any badly routed speedo cable or defective angled drive will cause the clip to break off, he also added that when he rebuilds these boxes he tends to use araldite to try and eliminate future issues
Will it pass an MOT with a non-working speedo I suppose is the next question

[Heuer]

No, it has to have a working speedometer and odometer to pass the MOT. A GPS or similar will not be sufficient. The T5 has a similar problem and mine failed because I had a Halda meter connected for the Rallye des Alpes. The extra weight on the speedo gearbox caused the clip to fail and, in the case of the T5, fifth gear to move out of play. I did drive it for about 200 miles before I understood the problem. The box had to come out and I got them to weld the clip in place.

[jivili]

David

Too be honest I already knew the answer before I asked the question ... just so frustrating as it was due to go for an MOT this weekend and after all the work to get it ready for this summer it really is a kick in the proverbials... absolutely gutted to have to rip it apart again

[kingzetts]

Dean,
I feel your pain. Some thoughts.....

David is correct that a non-working speedo is an MOT fail. BUT, your car would almost certainly pass because they do not actively test the speedo. Assuming they use brake rollers to test the brakes, the car will never be "rolling" fast enough to bring the speedo to life anyway, and that's the only time the tester could notice a non-working speedo. The "web" is littered with anecdotes of recent MOT passes with duff speedos, and my local tester confirmed this with me in conversation.

So one option for you is to have a go at the MOT and then drive with a GPS speedo through the summer and postpone the work until wintertime. That's certainly what I would be doing.

The other thought is to have a go at one of these.....

http://www.digital-speedos.co.uk/e-type ... 2125-p.asp

...using a magnetic sensor pickup, or fit a similar sensor-driven speedo as used in kit cars and specials, which will use a magnetic sensor reading off a diff flange bolt or similar. Again the idea being to postpone your mechanical surgery until winter and not miss out on a summers driving.

Good luck!