Lsd

[mockujin]

Do all GSX's have front and center LSD's?

 

[steve]

No, the center VCU is standard. A rear VCU was an option and will have an orange sticker on the drivers door frame. A front LSD is only available from the aftermarket.

Steve

 

[mockujin]

ok, can you check for lsd without taking out an axel by just spinning a wheel while the car is up and if the other wheel spins the opposite way its an open diff and if it spins the same way its a closed diff?

 

[nutshot]

Or if yer car has ABS, it does not have LSD on the rear, if it does not have ABS, then it does have LSD on the rear. And, yes, the tire spin does tell you.

 

[steve]

Only if you disconnect the driveshaft. With the driveshaft attached the friction can cause the diff action to override the VCU action and the test will give a false negative.

Steve

 

[nutshot]

Im not too sure on that one, Stevo. Perhaps my test was an exception to the rule, but spinning the driver rear on my TSI w/o ABS spun both rears while the car was in the air.

 

[steve]

Originally posted by nutshot
Im not too sure on that one, Stevo. Perhaps my test was an exception to the rule, but spinning the driver rear on my TSI w/o ABS spun both rears while the car was in the air.

I'm quite sure. The service manual procedure for testing the rear VCU requires you to disconnect the driveshaft from the rear diff input. I have a rear VCU and it doesn't spin the tires in the same direction unless I disconnect the input. I know some people don't seem to have to but it can cause false negatives based on personal experance.

Steve

 

[nutshot]

Hmmm... Okay. :shrugs:

 

[mockujin]

well i was in the junkyward a few minitues ago and i camm across a GSX, so i found some rims to put on it and i did the spin test and at first the wheels spint the opposite way but i seen that the driveshart was block by the hangling muffler so i moved it and then they both spun the same way, this was a 90 talon AWD. It seems like if it they both spin the same way regardless of if the diff is connected, it has a VCU?

 

[steve]

I would assume so. two other factors to keep in mind are Automatics have different gear ratios than Manuals so the rear diffs don't just swap and pre-'92 have 3 bolt rear axles which are somewhat weaker than the later 4 bolt axles that are the prefered upgrade to '89 to '91 AWD rear ends.

Steve

 

[mockujin]

ok, well could i use this 90 talon rear end and do a 4bolt conversion?

 

[steve]

No the rear diff is part of the conversion.

Steve

 

[mockujin]

oh, ok, well the rear diff only cost 22 buckz from a the junkyard, so its not a bad buy.

 

[steve]

As long as your not pushing big power the 3 bolt rear is fine. Like Nutshot was saying make sure you don't have ABS before putting the rear diff with LSD in. The two are not compatible in pre-'92 versions of the ABS.

Steve

 

[mockujin]

i do have abs. so i need to get one from a newer year?

 

[mockujin]

what makes them not compatible?

 

[steve]

The ABS in '91 won't work with a VCU in the rear diff. I don't remember why exactly.

Steve

 

[mockujin]

i dont see any reason why it wouldnt, because
doesnt the abs system disable the the accelerator anywayz,?

 

[NOSNUSE]

No ABS keeps the wheels from locking up, it cause the brakes to grab and release quickly so as not to lock up the wheels and cause you do skid, they say it gives you better control of the car.

 

[mockujin]

i kno that, but the reason mitsu didnt put them in the 90's is because they didnt have there little hack for it to work with AWD, so what they did was make accel disable when you press the brakes, but i dont see how having a diff would interfer with the ABS.