Using a GM R28 box, which takes a lot more pounding than its humble figures sugest, but it obvious is not keen on high temps.
So me thinks I'm in need of some gearbox cooling. Sugestions please
Having run the WLR at high speed (very) for and hour or so without gear changes the gearbox decided the gears should no longer be available. Finally
find one after a lot of shoving and pulling and clutch pounding. We toodled along for 10 mins and they all came back. They were fine for days until
yet another long high speed run gave a repeat performance of the problem
Using a GM R28 box, which takes a lot more pounding than its humble figures sugest, but it obvious is not keen on high temps.
So me thinks I'm in need of some gearbox cooling. Sugestions please
External electric pump running through a 13 or more row oil cooler would be a good starter for 10 I reckon.
is there a equivalent auto box as some autoboxes have oil coolers fitted as standard and may be an option for parts but assume would still need an external pump of some sorts
I think a pump and cooler is a bit dramatic. An mr2 turbo gearbox cooler was just a length of external piping and good airflow. Convection did the rest.
I seen of electric bilge pumps being used to pump diff oil through coolers on Oval racers often without a proper cooler just a length of coper or
aluminium alloy pipe in the airflow.
If a gearbox is tightening up I would suggest it will be because needle roller bearing or bearings in main shaft aren't getting an oil, so
pumping oil out the bottom of the box and back in on top of the main shaft should help. Beware using a high viscosity oil as this will make
things worse, it might be worth trying Landrover MTF94 gear box oil.
quote:
Originally posted by deezee
I think a pump and cooler is a bit dramatic. An mr2 turbo gearbox cooler was just a length of external piping and good airflow. Convection did the rest.
I have got the same box on mine and never had a problem even when it's been thrashed to within an inch of its life. Have you made sure the cooling ducts in the front edge of the bell housing are not blocked?
The Powertec in my Fiat has no cooler fitted, Quaife recomend I use one, that will be something to do with it costing £380+vat
MydT9 ran it in his stage rally car without overheating problem, this point was discussed not that long ago, and he suggested arranging cooling ducts
at the box , and close oil temp monitoring to see how it all went.
I've seen a few racing 3 series bimmers with diff cooling - frequently it's a mechanical pump ran from a pulley from the drive shaft to an
oil cooler. If it's over cooling, you can just block a few rows.
Worse, I've seen someone just fit an oil cooler to the diff, not realising it needed pumping 
I'd definitely go for sensible cooling (pump, cooler) - for the sake of a couple of hundred quid it's better than mullering a gearbox. It
gets scary if they seize at speed.
I'm even fitting a fuel cooler to my injection setup when it goes in.
[Edited on 13/9/12 by FuryRebuild]
Just "maybe' :-) it could be the swill masquerading as oil that you have filled the poor thing with.
Tripped over that one my self on my Moto.
Freshly rebuilt and filled with Yamalube 10/40 (factory spec by the way).
Gear selection became problematic as engine temps got into operating range and after a half hour,
gear shifting was almost impossible.
Not fun in traffic.
Refilled with GL4 gear oil and ALL issues vanished instantly. Lesson learned .
Cheers guys
Will try the simple stuff first. Oil refill and cooling ducts checks, thinking of building a ram air cooling vent to feed the gearbox more air.
Then onto oil coolers and pumps if that don't work.