904 transmission slippage

[Dave81]

Took the car out yesterday for its first prolonged drive of the year. Car was fully warmed up.

In Drive i have no issue.
When i manually shift from 2nd to 3rd under full throttle it slips. RPM rises and it eventually drops into third with a screech. Did this twice and decided not to push my luck.

Under part throttle it changes as you would expect.

I cannot recall it happening from 1 to 2, but most of my fun was done in 2nd gear pulls from 20.

Any advice welcome?
Im looking to manually shift it down the track this year to see what i can pick up in the 1/4, so the above is a big issue.

[Blue]

To put it bluntly Dave it's in trouble, slippage and any noises are always bad news, I suspect the high gear frictions are shot. It is possible for the trans to operate ok under normal driving until it gets really bad. It needs to come apart to see whats going on.

[Super Sloth]

Check your fluid level and colour.
Needs to be warm and the engine idling in neutral when you dip the stick IIRC.
Fluid should be a nice pink or clear colour. If it's brown and stinks then that's not good.

[Blue]

Colour of the oil isn't definitive, brown or black and it's definatly in trouble but it can still be red and on it's way. Noises are always terminal usually indicating something is running metal to metal.

[Dave81]

Bananarama!...........i knew that somethin wasnt right on the second attempt and feared that it may be a bigger ££ issue.

Car loves to fight me at every corner.........

Will do fluid check anyway, but it had a refresh kit in it 2-3 years ago with filters, gasket and new fluid.

[MilesnMiles]

That’s tough, Dave. I’m with Blue on this. Noises are trouble. Banshee wail from mine was the sprag going for a walk. Time for some new parts it seems. At the end of the day you intend to put more power through the motor so it was probably just a matter of time.

[Dave81]

True Miles.......Just wanted one more season out of the block and box before i upgrade.

Off to look online at bits then.........

[Blue]

Pretty much all you need here,
https://www.ebay.co.uk/itm/A904-TF6-Tra ... 1438.l2649

https://www.ebay.co.uk/itm/TransGo-TF-2 ... SwH3haAj8f

A deep trans pan is about the only other thing you might want to add and you've got you self a good street/ strip 904.

[Dave81]

Blue i owe you one.....

Already decided on the TF2 kit but had issues finding the uprated rebuild kits.

What are your thoughts on TCI Master Racing Overhaul Kits out of interest. They dont seem that highly rated on FABO?

[Blue]

The TCI kit is pricey in as much as it’s only a partial kit, that’s not everything you need for a full rebuild. That kit I have suggested is the most complete I could find and all the frictions are Alto which is the best quality. I already had that bookmarked for when I come to do mine.

[Dave81]

The TCI kit is pricey in as much as it’s only a partial kit, that’s not everything you need for a full rebuild. That kit I have suggested is the most complete I could find and all the frictions are Alto which is the best quality. I already had that bookmarked for when I come to do mine.

That'll do me bud. Was just curiosity about the product thats all.

Noticed quite a few of the Racers were talking about having Alto Red Eagle clutches etc in their transmission builds. Most guys were running in the 350-550hp range and into the 11s. If its good enough for that.....Thats what i'll go for.

[MilesnMiles]

Dave, I think you'll be pleasantly surprised by the TF2 kit. I have one in my 727 and it's quite a beast. Shifts hard with no overlap and will also make your car more viable when you get to the strip; great for manual shifting even with a column shift.

[Johnny Dart]

The Alto Kit, Blue has suggested is the one I imported, it has all the parts you will need. I bought the big kit with all the bushings etc..
Sadly my 727 box is still sat on the bench, a year and a half later waiting to be rebuilt.

[Dave81]

Thanks Chaps,

Ordered the TF2 Kit and Performance Rebuild Kit that Blue highlighted.

Also gone and bought a TCI deep trans sump kit:
https://www.summitracing.com/int/parts/ ... /overview/

Hopefully thats the whole trans sorted/Upgraded.

Should see some progress between now and the NATS.......Watch this space!!!

[Birdman]

Nice one Dave, it will keep Jim busy. Chris