MK2 caddy pickup with TD conversion - Gearbox help needed!

[GT-2047]

Hi all,

I have a '98 MK2 Caddy pickup (Felicia pickup) which i have just completed an engine conversion on (now running an AAZ TD lump from a MK3 Golf). I am still using my standard gearbox in the truck, however the problem i have is that the standard clutch cant handle the extra torque from the TD lump (I have a tweaked pump).

Please could someone who has any experience with this conversion advise me what i can do to upgrade my clutch?! I'm at a bit of a loss!

Thanks in advance,

J

[Phil-E]

Are you using the diesel gearbox?

What power/torque is the engine pumping out roughly?

Phil

[GT-2047]

Yes, it's the standard 1.9D gearbox that comes attached to the original AEF lump. Not sure on power, But i would estimate circa 100bhp (AAZ with tweaked pump)?

[Phil-E]

I would personally say that may be a little too much for the box itself.

I don't think there's much you can do in regards to the clutch short of measuring everything up and finding something of similar dimensions that will bolt on.

I have heard of felly derv boxes being destroyed by TDi conversions. Turn the pump down a bit. 90hp is pretty safe really.

Phil

[rolo]

Still on the first gearbox with the tuned tdi. Clutch took a while tho. Both the 16v and the mtdi pickups are fine gearbox wise although I`d like a higher dif in the diesel.

They are obviously much stronger than the polo and, after using them, would say as good as the O2a vw except for the lack of options final drive wise.

With 195/65/15`s 100mph is 4k revs so its not that bad. Just fitting a diesel one to the 1600 tc petrol to see how it likes that final drive.

Oh and a tip from jimbo, I think, gearchange is better with ATF lubricating the cogs.

Would like to contact these people who have broken boxes with a tdi to find out what gives and see whats lacking.

Edited 4 August, 2012 by rolo

[djaychela]

I think the Felicia box is fairly good - the weak point is the synchros, which are easily broken by trying to change gear too quickly, but other than that they are a good box (as long as the 5th gear nuts stay done up!). Back in the day the only breakages I had with them was from trying to force the box too quickly, particularly in 2nd. When taking the changes easier, they haven't given any issues, and that's been with a variety of tuned engines in the car, and with some fairly severe rally abuse.

Phil - It's torque that breaks boxes, not bhp, for the record.

[Phil-E]

I think the Felicia box is fairly good - the weak point is the synchros, which are easily broken by trying to change gear too quickly,

Phil - It's torque that breaks boxes, not bhp, for the record.

Yeh I was just thinking that if the power is at that level then the torque must be fairly high. And that's probably why my box has munched itself... it's a lot of torque for the box to handle especially with an aging DMF etc.

And agree about the changing too quickly.

I remember in felly if I changed very quickly it would crunch a bit like the syncro couldn't keep up. Took it easy on the box after it did it a couple of times then never had any problems once I knew to change slower.

Phil

[rolo]

You have a dmf on a felly?

[felicia16v]

I think you are stuck with the std diesel clutch unless you can get helix to make a higher load pressure plate or get a bimettalic one made up but either are not cheap options, you could maybe try to fit an extra diaphragm in there (helix did this with an old ford conversion I had in a estelle once).

the box's themselves are plenty strong enough but syncro's will suffer with abuse as will any gearbox and ATF does help lots with a higher mileage unit, diff bearings may suffer more with tdi torque and the older non diesel casings flex a bit around the diff but this was fixed and beefed up in time for the diesel engine.

mix and matching from fabia gearbox bits is possible too with care and don't forget the fabia 8v box bolts up to the skoda engine but may need clutch and flywheel adjustments to work properly.

[rolo]

Will just add for newcomers that the mtdi pickup (vnt,216 nozzles, expansion 4.5" downpipe,3" straight thru, seriously modded 11mm pump, crank girdle), is held in check via a multi paddle drive and 2 piece helix race cover sat in machined up diesel flywheel.

[Felici]

On 02/08/2012 at 13:25, Phil-E said:

I would personally say that may be a little too much for the box itself.

I don't think there's much you can do in regards to the clutch short of measuring everything up and finding something of similar dimensions that will bolt on.

I have heard of felly derv boxes being destroyed by TDi conversions. Turn the pump down a bit. 90hp is pretty safe really.

Phil

I currently and looking for a full diesel swat. Turbo of some for is there a complete truck I can buy for my Skoda I r gonna to deep o. Ish. I’m x