Race Engine Forum UK

Hello all,

Can anyone point out the weak spots on a 124 1800 5-speed gearbox? What can be done for strengthening?
I have some concerns about lifetime of my gearbox when the engine (hopefully) will make about 275 hp later this spring. (Even if the car weight is only 620 kg....)

No chance of that box surviving. Weak baulk rings, synchro hubs. Inescapably weak gearbox, 275bhp will shred it.

Use the Fiat 131 5spd.

GC

Ohh.... OK. Off to the scrapyard, then.

Thanks, GC.

Btw, great video!

thank you
PeterC

I´ve located a 5-speed gearbox from 131 2000 supermirafiori. Is that a good choice for my needs?

PC

yes, 131 2l Supermirafiori that's the one.

Drain and refill with OE Fiat ZC90 oil only!

Check it shifts before fitting, but good news is I've never heard of one go wrong. make sure the bearing in the end of the carnk is in good repair. If it's a Lancia TC origin engine (from Beta or similar) rather than Fiat TC I need to know.

GC

BTW I have small stock of new clutch cables for that car (might fit yours). had ot get new now, had a batch specially made and got stuck with them.

Guy, Hi

Sorry to butt in on this thread but I have a similer concern with the gearbox and drfferential are is in the 78 124 spider I am building. I expect around 160 hp @ 7500-7800 from the 2051cc mill. Will the stock gear box survive? If not what are my choices in the states that will be a direct swap or at least a close exchange.

Best Regards
Robert

It will survive only if you are gentle on the synchromesh when you change gear, race the change and you'll lose 3rd gear after a while.

I think the 131 2 liter 5sp garbox came in the (is it) Brava or Super Brava as it was known Stateside?

I'd ditch the 131 box immediately if it was me.. there is some written on this website about the conversion. It bolts straight up, same starter and cable, carries the 124 mounting underneath, tunnel needs enlarging near top of gearbox, propshaft front section needs to be shortened (131 box is longer) and balanced, on my 124 CSA I had to put a bulge in the tunnel by my left leg (LHD car) for the rubber donut joint too.

I'd be trying someone like Kelly Dicker in Napa or Bruces Parts Bin, both early members here, check the member list.

GC

Guy,
Thank you again. I will see what I can find in Napa as I have family near there.

Robert

Robert,
The driveshaft from an automatic Spider is the proper length for the 131/Brava gearbox conversion.
Now you know why they made those automatic Spiders! :-)
bye,

Csaba
Fort Worth, Texas, USA
'71 124 Spider, much modified
'67 850 Coupe, awaiting TC transplant

To reclaim my thread...... ;-)

I´ve now bought a 131 2000 TC gearbox, 5-speed.
Payed £70 for it, which might be a bargain since it only had 6500 km, guaranteed! "Dry-testing" felt like a hot knife i a can of butter ("varm kniv i en smörbytta" (Swe.))

Hopefully it doesn´t differ to much in length from the 124 gearbox. Maybe i´ll follow up with some pictures of the swap.