im currently converting my 83 gtv to twinspark running gear and have the gearbox ready for installation. i have searched the this forum and others but havnt came up with the awnser im looking for.
when putting a ts gbox in gtv what needs to be done so the speedo can work as normal? the ts speedo pickup has 3 wires where the gtv has 2, the ts pickup is plastic so im hopping 1 of the 3 is an earth and the other 2 wires get connected to the plug in the gtv. is this the normal way to go about it? i noticed a box under the back seat of the 75 does this need to be used aswell?
cheers, Brad
A 3 wire speed sensor is usually a hall effect type, whereas 2 wire is reluctor.
The signal output between the two types is very different, I don't suppose the sensors are interchangable?
no there not :( local alfa mechanic vagley told me it should work (earthing 1 of the 3 and conecting the 2 reamaing to the 2 wire gtv plug) anyone else??
Brad, here's a thread which discusses the swap and the speedo issue your having... good luck
http://www.alfabb.com/bb/forums/engine-conversions/162720-116-twin-spark-conversion-thread.html (http://www.alfabb.com/bb/forums/engine-conversions/162720-116-twin-spark-conversion-thread.html)
Also found this whilst surfing which may be of interest and give some pointers for the swap???
http://www.alfacentro.com/features/twinspark/index.html (http://www.alfacentro.com/features/twinspark/index.html)
Just found another on our forum...
http://www.alfaclubvic.org.au/forum/index.php?topic=5023.0 (http://www.alfaclubvic.org.au/forum/index.php?topic=5023.0)
You can fix it electronically or fix it mechanically - neither is entirely straight forward but if the box isn't being comepletely rebuilt/modified then the electronics is the way to go....
I know there is a lot on alfagtv6.com about various approaches and in particular an electronic interface module from Dakota Digital that is proven in doing this job (note I haven't used it myself).
And MD will probably chime in with some first hand experience if you can't find his posts there (I think it was there - the internet is too big!).
Ah - I see MDs post was here - Jesus has of course ;) found the correct path/thread....
cheers for the help and links.
hmm, the speedo issue is sounding like it will be a big headache :-[
as i want the car ready to drive in no more than a week im going to put the gtv gearbox back in the gtv but with the TS dedion for 5 stud hubs. when i have the dekota in my hands with the manual and i know how its going to work i will swap the TS box in.
cheers, Brad
Hi Brad,
Like Darryl said you can get some sort of black box and fix it electronically or mechanically. I had mine done mechanically and this requires you to take the TS shaft along with the original shaft so that Vin Sharp can swap the sensor ends. I chose this option as I wanted to have the parts inspected. This turned out to be a good option as one of the gears had a tooth missing. I also installed new syncromesh.
In addition I had to modify the wiring connectors on the reverse gear sensor so that I had working reverse lights.
Tristan
Hi Tristan, thank you for the info!
i did however see my mechanic today and he advised me on how to change the selector rod over, so i did and whilst gearbox was apart i noticed the speedo pickup (trigger wheel) on the end of the main shaft, i then had the idea of swapping main shafts with my gtv gearbox solving the issue, however as the pinion is on this shaft i may need to change my crown wheel to suit the pinion. but first id like to know what a 1983 gtv's diff ratio is? im lead to beleive its 4.30?? i would prefer to pull a part an old gearbox i have, can anyone confirm that a 1978 gtv's diff ratio is 3.91?
cheers, Brad
Hi Brad,
I totally forgot about the selector rod. My TS box originality has the iso-static selector. For simplicity I swapped the selector rod over to the original selector and it has since worked without issue. Be careful putting the selector end onto the gearbox as the spine has no key way and its easy to be one spline out. Marking it prior to removal would be a really sensible idea.
As for the crown and pinion, I'm not sure if the ratio's are compatible. Crown and pinions are also a couple. They ware together and most documentation I've read recommends to swap both the crown and pinion for new if either component becomes damaged. If you can use both the TS crown and pinion I would go down this path for the sake of reliability.
Tristan
do you have pictures of both senders ?
well, i have done everything, even swapped 5th syncro onto 2nd. but can not get the gear assembly back into the rear housing, no matter how much i jiggel, tap and move the selector rods around ??? >:(
I wanted to keep the isostatic linkages as mine were in great shape and so installed a Dakota Digital (little black box). It was a very simple install.
I can vouch that you can't just swap a crown and pinion from different boxes! I tried (and failed!). It was fine at idle but once the revs started to pickup the vibrations and a horrible whining sound was too much. Lesson learnt.
interesting, did you swap a matched pair (crown and pinion) over? or just install a different pinion with a differnt crown?
Not a matched pair. I can't remember why but for some reason I tried installing a different pinion with a different crown. They appeared to match well (i.e. there was no visible reason why it shouldn't work) but the result was very short lived!
ok so found the problem, the bearing and 'race' was 0.75mm bigger diamter so it would not go in, pulled the bearings original race from the donor gearbox and installed it, all went together like a glove. i also put the matching crown wheel in just to be safe, and shimmed the lsd centre up slighty, i would like to thank llyod from sirius for his guidance :) im happy with the result, as i learnt to rebuild the transaxle, shimme up 105 and TS lsd centres and solved the issues of speedo drive and shifter linkage! hopefully can get the car going tommorow ::)