Thread: LT95 Synchros

If its a used box I would replace them Steve, it's not a big job to do if you have it dismantled and inexpensive. Usually if the synchro sits lower than flush on the cone running surface it will need replacing. Check the condition of the gear dogs, any wear on them will indicate that the synchro is not working properly. Make sure you use new snap rings on the front and rear of the mainshaft when you reassemble it. Also check the endfload on the front and rear of the mainshaft before fitting the snap rings, this can be adjusted with different size thrust washers (the ones under the snap rings).

Be careful when you buy new ones the poor quality of some of the ones you buy today makes them worse than the old ones.
Make sure you buy good quality ones there is a lot of rubbish out there.

Originally Posted by Bearman

If its a used box I would replace them Steve, it's not a big job to do if you have it dismantled and inexpensive. Usually if the synchro sits lower than flush on the cone running surface it will need replacing. Check the condition of the gear dogs, any wear on them will indicate that the synchro is not working properly. Make sure you use new snap rings on the front and rear of the mainshaft when you reassemble it. Also check the endfload on the front and rear of the mainshaft before fitting the snap rings, this can be adjusted with different size thrust washers (the ones under the snap rings).

Thanks Brian.
Are the gear dogs you're referring to the small teeth that look like the ones on the synchro rings?

Whats a reasonable sort of price for quality synchro rings (ie I'll steer away from anything really cheap)?

Steve

Originally Posted by steveG

Thanks Brian.
Are the gear dogs you're referring to the small teeth that look like the ones on the synchro rings?

Whats a reasonable sort of price for quality synchro rings (ie I'll steer away from anything really cheap)?

Steve

Thats the ones, they should be shaped the same as the synchro teeth. if they are chipped or worn you should replace the gear, check the synchro unit as well (the steel sliding bit) as damaged gear dogs can indicate wear or damage on the synchro unit also. Tried to find the invoice for the last lot of synchros I bought from BMI Sydney but cannot find it - I think they were about $20 each. Check each new synchro on the gear before installing and replace any that sit too low, as I have even seen genuine new ones that aren't up to scratch.

$20 would be nice, but I've phone a few places (including BMI) and prices seem to be around $65-75. Might have to get them direct from the UK.

Thanks for the tip on checking new ones actually fit OK. I wouldn't have expected that!

Steve

Steve
I know that all 4X4 in Newcastle only use good quality ones when they rebuild them because if they use rubbish it comes back on them.
I was just quoted $50 each

A lot of manufactures will give a minimum clearance between the brass ring and the gear. Some gearboxes use the same ring on all gears. In this case you can just swap 4th for second as 4th does little work.

I agree with an earlier post on dodgy rings. I have rebuilt a few series three boxes and when I used non genuine rings it was a bit of a lottery. Some would be good, others woeful. I will only use genuine LR rings, although many years ago, were not much dearer than non genuine.

Another tip when building a gearbox is to deglaze the steel part of the gear that the brass ring grips. Get a medium grade emery and rub it on the steel part. If the gear and the brass ring are cleaned of oil and are dry, turning the brass ring with a bit of pressure it should grab and lock onto the gear.

Dave.

Thanks for the tips Dave.
The LT95 uses the same synchro rings for all gears, so my plan is to buy new ones to put in the good box, and use the least worn ones to put the second box back together as a reasonable spare.

What was the actual issue you had with the non-genuine rings. Just a bad fit etc from the start, or looked OK but poor material and wore out in a short period of time?

Steve