Thread: TeamFA's Gearbox Repair '02 Defender R380

Good on you. I haven't tackled a modern gearbox yet and don't really want to!

Very interesting and good thread, thank you, it is well timed for me as I am about to decend in to the bowls of my GB & TC. Having already completly stripped the motor for a rebore and total rebuild!! I have a big project ahead of me.
I note that Croft state that the R380 56A J has a few short comings?? mine has been fine to date and only reracing it because I have it out and it has done a fairly heavy 350Ks. Can some one tell me if while I am in there can I upgrad to the L specs, or is it a total different set up.
Can you tell me the weight of your big plastic box and how much freight was involved. Did it have more than the GB bits and clutch/presure plate in it. What is a Solid Flywheel Conversion??
Thanks Peter

G'day Peter,
Not sure of the gearbox differences - but I've come across a few different threads here on the forum that go into the differences.

My big plastic box cost me 120 GBP to deliver, I'm at work at the moment, but will let you know the size and weight this evening.

Even with this shipping cost, a saved a substantial amount of money compared to buying locally. A shame, as I would prefer to support local businesses, but when the price differential is so great, it's a difficult ask.

The solid flywheel conversion is only if you have a dual-mass flywheel currently - do you know what yours is? A standard solid flywheel clutch setup has a solid flywheel, with a multi-layer clutch plate that has a spring assembly built-in, that assists in removing vibes from the engine pulses to the transmission. A dual-mass flywheel arrangement puts the springs into a flywheel that's made up of two wheels, and that part absorbs the vibrations.

The economic difference is that a solid flywheel can be machined, so a clutch rebuild is a cheaper option. A dual-mass flywheel can't be machined.

Hopefully somebody more knowledgeable will be along shortly...

I spent about 5 hours yesterday correcting a mistake I made.

I had noticed a slight oil weep, coming from the lower part of the join between the transfer case and gearbox.

Nothing for it other than coming off. I had a think, and decided to see if I could seperate the gearbox and transfer case enough to have a look, without taking either completely off.

First I removed the propshafts, tunnel (and subsequent transfer case linkages), transfer case oil breather, and earth lead. I then removed the 4 bolts from the t/case chassis mount to the t/case. I then removed all of the nuts/bolts holding the t/case and gearbox together.

At this point, the lowest bolt hole proceeded to flow oil. It was after having a good look at the assembly that I realised where my mistake had been.

This particular bolt (like some others) actually goes through into the t/case, not into webbing on the outside. The lowest one actually sits below the t/case oil level.

This is the first time I've come across this. In my case, I didn't apply any gasket to the metal around the lower hole, I must have made an assumption that it was only going into webbing at that point.

I was able to creep the t/case backwards, still supported by the output shaft and sliding along the chassis mount, enough to get about 20mm clearance, confirmed the bit I'd missed, cleaned it all up, and re-applied gasket to the entire surface.

20-minute drive later yesterday afternoon is showing no leak at all, at this stage, so hopefully it's fixed.

So 5 hours wasted to correct a silly mistake - one that will never be made again!

Peter, attached are the pics of the tool solution I used to undo the grub screw from the selector assembly. The hex bit probably isn't the correct size, but I just grabbed one to show you what I was talking about.

In other news, I seem to have fixed the gearbox/TC oil leak. The only leak I have left is from the gearbox drain plug, but I was lazy and didn't gasket or replace the crush washer, so my own fault. I'll pull that out and drain, then gasket and replace, then top up again.

Cheers all!
Michael

Thanks Michael, I am still a bit unsure if I should be going into the GB. Doing a complete rebuild on the motor (350 ks) I don't want to have to go back latter and do the GB. The only indication of anything askew is that selecting third has been a bit notchy and keeping in mind the old saying
" if it ain't broke don't fix it" My concern being if I am only replaceing worn parts how well will the box setup again with the mix of parts.
The other ? for anyone with an opinon is taking the bore out by .040 (max) and fitting a Turner performance head, will the Injector pump need adjusting
Peter

I was forced to go into mine, otherwise I wouldn't have, but mine has only done 100K kms.

The selecting third might just be a bias spring adjustment issue - have you checked that out yet? Plenty of information on the forums here already, and the workshop manual covers it pretty well.

That grub screw was the only nut/bolt that gave me any concern in the whole job. Everything else was straight forward.

The only thing that really surprised me was the amount of force required to pull the oil seal collar off - you can see pictures of the 20-ton press I had to use to get it off, in combination with my new gear puller set. I would also suggest that if you don't have a good set (or equivalent, I'm sure there's a lot of choice out the), then removing and replacing the bearing would be extremely difficult, if not impossible. I wouldn't have made it as far.

As far as I've been able to determine, the mix of new and old parts shouldn't be an issue, as long as you correctly adjust for end float, as per the manual.