Diff Centre Swap

[super zook]

Hello ive been looking around here for a while and can't seem to find what im after in the way of diff centre swaps.

The situation is i have a 1981 sj40 sierra. I have been told that lockers wont fit my particular model diff. Im wondering if i can swap the rear centre for a later model version the same ratio as what i already have up front?

Cheers.

[muppet_man67]

no you will need to swap the entire diff including housing and center. Im not sure about axels. find yourself some 1.3 narrowtrack complete diffs. they will bolt up relatively easily. you may have to swap the flanges on your drive shafts.

[nicbeer]

Only prob u will have is ratios. NT ones are 3.9 and WT ones are 3.7. i believe urs are 4.11

cheep fix is to weld the rear or front centre up. Christover1 on here uses dual welded 1 ltr diffs i think.

cheers

[muppet_man67]

he does. he has power steering for the front.

[super zook]

So there is no chance i can modifiy the ones i got, cheaper than just getting new ones?

[muppet_man67]

So there is no chance i can modifiy the ones i got, cheaper than just getting new ones?

the flange on a 1liter housing is a different diameter to a 1.3 liter housing. 1.3 liter centers will not fit in the hole so to speak.

[super zook]

so ill put wide tracks in or go "fully sik" with hilux diffs and 235 mtr's

[muppet_man67]

or keep it simple and weld up the rear. I have heard that you may be able to get lockrights for 1 liter diffs. you would be best to contact a supplier to check it though.

[Podge]

Definately no Lockrights available for the 1l (at the least the ridgy didge ones from the US). Powertrax did make them but there was too many failures (diffs detinated) so they were taken off the market about 8-10 years ago. That is the only aftermarket diff lock that I have ever seen available for the 1l. Suzuki did make available electric units for 2x overseas markets.

[christover1]

On a related matter, you can easily fit LJ diff ratios to 1.0 litre diffs.
Doesn't solve locker problem, but does give choice of 4:6 or 4:9 diff gears. Mine have 4:9's in them.
Clearance is better on the smaller 1.o litre diffs, meaning tyres dont need to be as big.
If you still have 1.0 litre engine, I wouldn't weld both diffs, or too much power is lossed, especially with larger tyres.

christover

[super zook]

i got an 83 diff with the car it has disks rather than drums the guy said that they were the same but now that im about to put it in im not to sure can anyone tell me if they are the same ratios or the same stated above on the other reply thanks

[Gutless]

its most likely the same ratios as yours, just the disk brake version.

I thought you could get detroits for 1litre/ LJ diffs?

[BenT]

Are you guys sure there is no lockright available for the 410? I know a couple of guys with them...

Look at the Rocky Road outfitters web site:

http://www.rocky-road.com/zuklock.html

In the drop down box there are SJ410 lockers for $215US

Ben

[super zook]

thanks for the reply, mine is a sj40 im pretty sure not a 410 when ever i ask for parts they never have it listed . what year did they redesign the diffs/go to 410? was it only when they came out with the wide track? thanks again

[sierrajim]

Please be aware that welded diffs are illegal for road use.

That said, Chris' zook with welded centres has the ability to drive pretty much anything (could be the driver) but the car is very capable.

[BenT]

Well, I've never heard of an SJ40 before, but as far as I'm aware, LJ80 and SJ410 diff heads are interchangeable, therefore I assume there isn't any other type off diff that was produced after LJ's and before 410s.

Are you sure is a SJ40?

Ben

[rgzook]

i'd be also checking the coily centre as when i blew my air locker i was able to fit a early centre sraight in same axles and all.

Might be an option