How many detents in a 124 gearbox?

[brettule]

I'm servicing my Fiat Spider 124 gearbox and have come to a section in my workshop manual which discusses the detent's. Out of my gearbox came
3 x detent balls
2 x detent dowels (1 short 1 long)
2 x interlock pins

However my workshop manual (http://www.amazon.com/Fiat-124-Coupe-Sp ... 1855200791) states that there should be 3 x detent dowels not 2:

"Remove the detent springs, then dump out the detent balls. Remove the short detent dowel.
NOTE
There are 3 detent balls, 2 long detent dowels, one short detent dowel and 2 interlock pins. See Figure 73."


How many should I have? My Fiat mechanic thinks there is only 2 but he's not sure. I guess the box ran fine with only the two but I want to work out of the manual is incorrect or I'm missing a part.

[JerryH]

I just completed a tranny rebuild this summer. My car is a 76. Mine had 3 detent dowels: 2 long and one short--just like your photo.

One of the dowels pushed against a switch that closed whenever the transmission was in gear. I think this switch was used in the EGR system. Perhaps if your tranny doesn't have this switch you may only need two dowels?

Hope this helps.

-Jerry

[brettule]

Ah-ha! That sounds more like it. I'll take a closer look in the next few weeks when I start cramming all the bits back into the box but with luck it's as you say - some redundant emissions stuff.

[brettule]

All sorted. The "spare" long detent dowel goes into the gearbox housing where an emissions control switch is on US models. No emission rubbish, no need for the detent dowel.