Thread: Ex Auction Gearbox Assessment Help

Bearman is the man.

Wish my transfer gears in my auction box looked like that!

The gnarly ones in the main box are on 1st gear.
I'm keen to hear Brian's view, but to me it looks like its just copped a bit of abuse and chipped the teeth.
Guess it could also mean that the syncro is worn out and ramming it into first gear required less effort than double clutching.

From memory there isn't a specific service limit gap between the bronze synchro cone face and the front of the gear (ie as the inside of the ring wears it will slide further up the cone on the gear and the gap reduces) but if you slide it on as far as it will go, check he gap and and then compare against the other gears it might give you and indication of how worn it is.

I'd say there's still plenty of dogs that have good sides on them and since its a complete box strip to do anything about it and the rest looks OK, If it were mine I think I'd just run it and see how it behaves.
If it was being pulled down for some other reason I'd definitely replace that gear and synchro while it was apart.

Steve

You would probably need to have a look at the inside of the brass cones to determine if replacement is needed, they look fine from the outside, and those gears in my opinion still have a lot of life in them.
They may be a bit notchy to change, but I defer to better qualified members on this.
I hope the CDL canister is OK, they are now unobtainable new.

G'day Murray. From the pictures it appears most of the gears are in pretty good nick except for 1st gear engaging dogs which have been doing a bit of crashing. Whether it's from synchro wear or just operator abuse is a bit hard to judge unless you can test run the box. My guess is operator abuse from trying to do fast gear changes. It's normal for those synchros to be very loose on the gear face and they float about freely. The fur on the magnet looks normal - as long as its not gritty or lumpy when you rub it between your fingers it is OK. The dregs in the transfer are possibly from being left out in the weather and no plugs in the breather holes after removal from the vehicle. Of concern is the bearing roller you found in the gearbox. That is a roller from the input shaft bearing that fits on the end of the mainshaft and has probably been dislodged when the box was being reassembled after a rebuild. I have seen this before in rebuilds and the box will be noisy (growly) in 3rd gear under power. I have attached a picture of the bearing for you to see where it came from. When you assemble these boxes you have to stick that bearing inside the input shaft with grease or petroleum jelly and fit the front cover complete with input shaft and layshaft onto the gearbox and it fits over the end of the mainshaft and supports the front of it. It you fit the bearing on the end of the mainshaft and then fit the front cover and shaft onto it then this can happen. Unfortunately you will have to pull the front off the box to fix it but no biggie on a bench. Things to check are
1..............clutch fork pivot pin for tightness
2..............Check oil pump is the later type with steel shaft
3..............replace that bearing (part 571062)
4..............check all the detent springs and balls are in place in the gearbox (under the top cover) reverse spring is different to the other 2 and usually has a yellow dob of paint on it.
5..............Push a 30mm welsh plug into the reverse idler shaft hole inside the transfer case to seal it.
6..............Check the mainshaft input gear and spacer in the transfer. Both should be loctited onto the shaft and be tight. The spacer should turn with the gear otherwise you will get the oil transfer happening.
7..............Check the gap between the rear fork on the intermediate selector gear is in spec ( 0.005") i think is the figure in neutral.
8..............Check the torque on the intermediate shaft bolt is in spec (125 ft/lb)
9..............Check the freeplay in the centre diff - you may need to reshim it.
10............Take the rear output housing off and undo a bolt on the centre diff and check for evidence of loctite. If none, take the diff out and loctite everything including the hi range gear on the splines on the front.
11............If you are going to use it in a 4x4 you will need to change both speedo gears in the rear housing.
front bearing 001.jpg

Hi Brian, your knowledge of these boxes is amazing, thanks for sharing it, I’m sure many others will find this info very useful too, given the number of Lt95a’s appearing from the auctions.
This box is for a long term project, so I’ll have plenty of time to check all the things you suggest.
I suspected that roller was from a bearing, but now it makes sense how it could get there.
I’ll be using an electronic speedo, so no worries with the speedo gears.
The fur on the magnet was smooth and pasty.
I’ll check everything else in time, but at a glance it looks like it will be a good usable box with no obvious major issues.
Thanks again for your help.

Cheers Murray

No worries, I have been playing around with them for about 28 years now and have learnt a few things about them. My guess is it was removed because of the noise in 3rd from that missing roller in the bearing but it also could be because of the crunching in 1st gear if it is a synchro fault. A common thing I see with 6x6 boxes is mainshaft spline wear under the transfer input gear from not being loctited. The 6bys are harder on the transmission being much heavier. If it's a long term job I would replace that gear and all the synchros and bearings. One thing I forgot to mention is to check the input shaft bearing retaining plates. If the box has been installed forcefully these plates get bent because the spigot shaft is not located into the spigot bush before tightening up the bellhousing bolts. Yoy can check this by pushing/pulling on the spigot/input shaft. Any lineal movement means bent retaining plates.