I blew out the rear differential on my 94 firebird 3.4l auto. i would like some info on how far into replacing the rear diff i need to go. it makes a horrible grinding noise from it so its pretty far blown. when i put into park after its in gear it grinds the parking pin down cause there are no brakes stopping the shaft from spinning please get back to me as soon as oyu can. if you can email me at [email protected] that would be great

Hey Jordan, Repairing a differential is a complex task..( to make it RIGHT and have it last)... Please take it to a qualified professional!!

remove the rear cover all the bolts except the top 1 just loosen that 1. Put a bucket under the rear diff and open the diff cover and drain out the fluid. clean and reseal the diff. remove the plug on the front of the diff and fill with the correct diff fluid until it is filled up to the hole and replace the plug, clean up and check for leaks. No leake = job is complete.

I can't see how that is possible given what needs to be removed to access the bearings. The rear diff is not very difficult to remove from the car

Your rear diff has a different ratio gear in it. Find out what ratio gear your car came with, remove your diff gear, and replace with same ratio that it came with from factory, that will fixya.

First replace the seal and case cover gasket, then top up diff oil, test to see if noisy is eliminated , because since the oil is leaking it might be running dry.

RedLine makes very good differential fluids.The fluid in the rear differential is going to be 75w140 and as far as the front differential,I would check with the parts store for that.It could be 75w90 or 75w140. You should get about 2 quarts of fluid for each differential.The transfer case is going to use Mercon V(5).About 2 quarts for that as well.

Sounds like your rear diff is winding up. possibly rear diff /or transfer box fault .

You need some gear oil put in the rear end!!!

diff lock displays on dash and is opperated by a dial to the left of the steering column. the center diff lock is operated by a button in the center dash and locks your center differential, making your front and rear driveshafts turn at the same speed. the front and rear differentials lock either your front or rear or both differentials making each wheel on the same axle turn at the same speed. all of these features are for increased traction in off road and wet conditions and situations

Hello, from your description it sounds like your front differential has, for lack of a better term, exploded! the grinding noise is the ring and pinion in the front differential trying to turn w/ the rest of the transmission but most or all of the gear teeth have been broken off. There are 3 sections of your transmission: the front section which is the front differential, the center section which is where all of your main clutch packs and planetary gear sets are, and the rear section which houses your tranfer clutches. Your front differential contains gear oil and the center and rear section contains auto trans fluid. You need to check your front diff fluid, this is the fluid that is most likely covering your undercarriage. Usually this concern can be repaired as long as the damage isn't to great, but to assess the damage the transmission must be removed and pulled apart. Here is a diagram of where to find your front diff dip stick.
The dip stick is located on the opposite side of where the transmission fluid dip stick is. It's yellow and you have to be standing on the passengers' side of the engine compartment, make sure the engine is cold so you won't get burned, not that you'd be driving it anyway. You must reach down just behind the bell housing on the side of the transmission itself and just lift straight up. I hope this info helps...(subytech1)...