JC5-089 and JC5-129 final drive

[Symon]

I have a gearbox issue with my car (172 cup) and I know where I can get a JC5-089 gearbox from a Phase 1 car.

I understand the main difference is the final drive ratio. Is the gearing taller on the JC-5-089 or the JC5-129

Also are there any other differences which makes one better than the other?


Sorry if this has been asked already. I did do a search but couldn't find a definitive answer.

Simon.

 

[mark123]

They are the same gearbox except for the final drive.
All the gears themselves are the same but the final drive makes them all slightly taller ratio.

 

[Symon]

Ok, thanks for that. Does it make much difference in the real world (on road not on track)

On my daily commute I do find the ratios a bit short, and it could do with a taller top gear.

 

[NorthloopCup]

You'll not notice much difference at all tbh. Might be slightly better on fuel at cruising speeds.

 

[Symon]

Excellent, many thanks. :up:

 

[Yanoo]

JC5-089 is slightly taller as said above. You can easily check the difference with my software: http://www.dp-automotive.hu/downloads.php?id=Setup_Renault_valtok_1_1.exe

 

[Ph1 Tom]

Better on motorways for cruising, noticably slower acceleration.

 

[Symon]

I think I would miss the acceleration.
I think the easiest route would be to get my box fixed, as decent JC5-129's seem quite hard to find for sensible money.

 

[NorthloopCup]

I think I would miss the acceleration.
I think the easiest route would be to get my box fixed, as decent JC5-129's seem quite hard to find for sensible money.

What's up with your box currently? I may be able to help as I have stripped and rebuilt a fair few of these now.

I'd stick my neck out and say that all the ones available on the market need a few new gears in them as well tbh. They might last you a year or so before anything became noticeable.

 

[Symon]

It is making a grinding whilst accelerating and often clunks whilst pulling away, I think it may be diff bearings as it happens in all of the gears.

I also get a tinkling noise from the box area at steady high speeds, like on the dual carriageway.

Gear selection is fine, when draining the oil there are no metal particles.

I have rebuilt a few boxes myself (not one of these though), and I am tempted to buy another, swap them over and then rebuild this one as a spare, or if I sell the car before using it just sell it on.

The annoying thing is, the box in the car was fine when I bought the car, but after only 2 weeks it started playing up.

I don't drive especially hard.