PIGG1E

I used the search but couldn't find wat i wanted

My E4 has a bit of a problem with the front diff . turning right the car is making serious clunking noise and feels as though the engine is gonna get thrown outta the car . when i jacked the car up and went to turn the left front wheel forwards it goes about 1/ 8of a turn and locks up . turn the right front wheel and it is sweet . but if you turn the left wheel backwards it is making a knocking sound.
Had a friend who knows not much about evo's say it might be the centre front diff .. and that there normally located in the bottom of the gearbox and that the gearbox may have to come out and be stripped down and diff replaced then all put back together .. when he told me this i said maybe it is the transfer box as i know they are a common fault .. but he was pretty convinced that the sound was coming from the centre front diff (he is a lot more mechanically minded than me so i can only go on what he has said) . So he said if we drain the gearbox oil and find some chunky's in there then we will know for sure that it is the front centre diff (he said he thinks it may be the spider gears as it is only doing it while turning right)
Anyhow have been looking for 2nd hand E6 gearboxes and then was informed that the centre front diff is not located in the bottom of the gearbox but is also in the transfer case !!! Is this correct and if it is correct does that mean that the gearbox will not have to come out to replace the transfer box ??
I will not be working on the vehicle but i like to know how everything works and what is needed for the repair . so if anyone out there has some kinda idea on maybe what it is and what would be involved to repair then any info would be great thanks

crcain

The center diff exists in both the gearbox and the transfer case

There is an open diff in the gearbox and then a viscous coupling unit in the transfer case. Chances are your problem is the front diff which also exists in the transfer case.

Drain the oil of both your gearbox and transfer case and look at the oil and drain plug for debris. The transfer case contains the front diff, VCU, and ring and pinion to the driveshaft.

94AWDcoupe

iTrader: (125)

The center diff is huge compared to the front diff. The front diff will break 100 times before the center diff breaks once. Your problem is going to be in the t-case. The front diff is broken.

PIGG1E

So does the gearbox have to come out to fix this or does it just have to have the transfer case taken off ??

94AWDcoupe

iTrader: (125)

just t-case.

TonyK94

barneyb

I'd look at the front diff in the transfer first. Stock, it came with slintered gears.

TonyK94

TonyK94

barneyb

I don't know what you have but the USDM Evo 8 has an open front differential - pure standard construction. I own an USDM Evo 8 but I've never had the transfer case apart but I've read on here that the reason it tends to fail is because the side gears are slintered metal. Slintered metal is ground up steel and I don't know what else, put in a mold and heated in a furnace until it fuses together. Its a cheap way to make a gear but not as strong.

With differentials, put motion in and motion has to come out somewhere else. So, turning one wheel and having the other turn is normal.

Bladey

watch this. It will explain what is going on, very common on evo 4-6's recommend replacing the tcase and while you're at it upgrade it with the bolts

TonyK94