Help on 124 spider gearbox needed ! (upodated)

[miro-1980]

This has been my initial entry. Now it has been to modified to present the issues in a more detailed manner after the response I got from mirafioriman (above) Thanks mirafirirman !    
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Guys

My 124 spider 1980 gearbox recently got bad.

Initially the problem was that the gearshift? lever was moving way to widely to change the gears accurately, We have changed the springs and rubbers in the shifter lever mechanism which took care of this problem but I always had a feeling that the 1-3-5 engaged "more deeply" while 2and 4 engaged in a more "shallow" manner.? Occasionally 2 would resist on a downshift from 3rd (this was taken care of by longer and making sure that the clutch is fully depressed) The? 4-th would occasionally disengage on a road bump, and with my foot off the gas pedal. Recently (after a transmission oil change) the problem got worse. the 4-th will disengages quite often and on quick downshifting from 3rd to 2nd gear there is clear resistance as if the clutch is not depressed. It still is manageable with more time taken to synchronize when shifting down from 3rd to 2nd and keeping my hand on the lever when in 4rth but it seems to require immediate attention. By the way even quick shifting from 1st to 2nd is no problem shifting and shifting to 1st, 3rd and 5th is just fine.

I have a feeling that 2nd and 4th do not engage fully. My current analysis is that this is a bearing retaining plate got loose preventing the gears from engaging fully and thus causing the problems. This was a typical problem with Polski Fiat 125 p which had a similar construction gearbox.

I am facing this problem and want to ascertain if this can be easily fixed and if not,? what gearbox I would need to buy (and where ?). I have found one guy that has a 124 spider gearbox with the "small bell housing". I would like to get it and put my bell housing on it. Does anybody know if this will work without modifications.? ?

Can anybody confirm? what I have gathered so far and answer some detailed questions on 124 gearboxes :

1/ there were two types of 5-gear gearboxes for 124 spider - early and late model ? when did they change ?

2/ Aside from internal differences they? had different bell housing sizes? (200 mm and 215mm) ?

3/ Are the bell housings interchangeable between early and late model gearboxes?

Any advice , suggestions?

Miro
? ?

[mirafioriman]

On the 131 gearbox in my car it used to jump out of first. I changed the detent springs (still available from Fiat a couple of years ago) and it cured the problem. Not sure about the second gear issue though.

[djape1977]

i had same problem with my 132 diesel gearbox (after 470.000km) and it turned out to be worn forks. changed the whole gearbox.
as far as i know, there is one type of 124 spider gearbox, and two types of bellhousings. bell housings are interchangable. if there's any other diference between these two types than i'm not aware of it. gearbox from fiat 125 special (wide horizontal taillights and 4 square headlights) 1608ccm is exactly the same. earlyer 124 units had the same small bellhousing as 125 special for 205 clutch plate and later units for a 215mm one as 131 and 132.
there is a rumor that fiat campanola (jeep like thing they made for army) has the same gearbox. this i haven't personally seen so it might be worth checking out if there were some in polish army. they're still widely used in serbian army and there are many on scrapyards...

in my experience, 124/125 gearbox suffers from poor design and production quality and sufers the same problems as 125p and lada gearboxes. perhaps it would be wise to consider a 131/argenta gearbox upgrade?

[miro-1980]

djape1977

Thanks, this is really helpful. I still need one and I am really considering getting a new one from spiderpoint unless I can find it on ebay. Are you sure that the only external difference between early and late models was the bell housing size to fit larger clutch assembly? Mine has a 215 bell housing and a guy says he has a spare gearbox with 205 bell housing. Can I get it from him and switch the bell housings ? Will this fit without any modifications ?

I was engaged in an exchange on this subject with Guy Croft who says:

"There were indeed 2 types of 5 spd gearbox with bellhousing on the 124 Spider. The early one - as fitted to the 124 1608 Spider (and Coupe) and the later one as used on the 1800 and 2L versions. You can play 'spot the difference' but you'd need to have them side by side! The later one married to an engine with a bigger diameter flywheel than the 1608 and thus had a roomier bellhousing. Don't know how different the gearboxes themselves were, suspect pretty much the same but they are not interchangeable in the sense that you need the early box and bellhousing with the early engine - and the late with its bellhousing on the others "

You both may be right in other words : small bellhousing will fit only old engine and large bellhousing to late models , provided bellhousings can be swapped between early and late model gearboxes.

Have you actually done it?? ? ?

Miro

PS I am looking into the Fiat Campagnola issue and will try to post results of my search next week 

[djape1977]

a friend of mine that was working on a 124 restoration job a year or so back (you saw that series of photos) , came to me looking for a bigger bellhousing and in a course of next few days we found out everything that there is to know on that subject by trial and error. also, when i fitted a 1.8 twincam into my lada i had an idea in the beggining to couple it to lada's gearbox. later i decided to throw in 132 gearbox along with it's 1.8 engine.
 so here is again what we found out:
there's two comletely different types of fiat gearboxes that where installed with TC engines 1)124/125 gearbox and 2)131/132 gearbox. both had some variations over the years, but nothing major.

1) was installed in 124 sedan (only with TC such as special T), 124 sport, 124 spider, 125 (4 speed), 125 special (5 speed), campagnola - undetermined
there's two types of bellhousing for that gearbox. 205 mm for all 1608ccm engines and 215 mm for 1756ccm and 1995ccm. bellhousings are interchangable. lada's bellhousing also fits that gearbox.

[miro-1980]

Thanks again , you have been very helpful.

 Now i need a new gearbox !

Miro