Sierra rear diff / suspension removal

All pictures are clickable for a better picture.
The car is scrap so i haven't taken care on the bits i don't need.


The sierra has been sitting in a farmers field for 6+ years. Half the v6 is missing, every panel has got a dent in it. The front and rear brakes are siezed solid, hopefully pads are rusted to the disks.

I took the rear diff off, as mine is starting to be quite jerky at low speeds due to excess backlash.

I was lucky removing this rear diff as i was able to have the sierra on it's side. having really good access to the bolts.
The main thing that helped me get the job done was a impact wrench with a few extensions. It made light work of the bolts and let me take the rear suspension setup off on my own. If you do decided to take it apart and have acess to a impact wrench - use it.

I hired 'free of charge' the impact gun (used to work at tool hire) 28v milwaukee. great piece of kit.

I didn't get any pictures of the car before i removed the rear suspension. just the car on it's side.


First thing i did was remove the exhuast, grinder through part of the section then bend it out this gave me clear access to the Prop and the rear diff mounting points.


Next was to disconnect the rear prop from the diff. The bolts were 'loose' i manganed quite easily to undo them with a 3/8 rachet, bit odd. I could only do 3 of the bolts at this time because the prop had very little movement in it because of the rear brakes being siezed.


While i was there i removed the prop bearing cover (to go on mine) and loosened the bearing out so the diff would have more movement once it was away from the car to let me undo the last bolt on the prop/diff joint.


Next was to remove the towbar mount because it saddles the rear diff mounting point which will have to be removed. The nuts didn't want to come off completely so the impact gun was made redundent for the grinder. The bolt heads are in the boot with some big washers to spread the stress. taking a grinder to the heads 3/4 were ground through then a hammer and chisel took off the rest of the head. The left over bolts were then hammered through and the towbar mount came straight off. This left the 4 bolts holding the rear diff mount in place.
Also remove the anti-roll bar links too.

 

Next it to remove the rear shocks. what i should have done was to undo the top mount in the vehicle before i had the car on it's side, it would have been easier as the shock would have just popped out. I had to disconnect the shock from the lower arm first before i could easily undo the top mount. With the impact gun and a spanner the bolts undid really easy.
At this point the springs are still under tension because the shock is at full travel, so when removing the lower arm shock mount bolt the lower arm with everything on it bounced out 4"+ (be carefull) same was done for the other side.
near side before removal.

I cut through the rear brake lines and hand brake cable at this point. Don't tell me off but i also cut through the ABS leads as the sensors are probably shot anyway.
The last thing to come off is the main suspension mounts. I thought the car was resting on the rear nearside wheel so great care was taken when removing the bolts. Using the tractor to hold the car off the ground with spare wheels under the near side taking most of the weight. Using the impact gun again the 6 bolts came out very easily. The off side mount popped away from the chaissis with very little problems, the near side was not that easy.
The main mount has a locating shaft in the bush that sits in the chassis. the off side had rust in. After much levering and pulling the bush came off the shaft leaving it on the chassis.  the rear suspension was now free from the car except the last bolt on the prop/diff joint. I undid the 4 bolts completely and the joint stayed together. supporting the suspension and hammering the joint came undone. letting the rear suspension fall to the floor. job done

 

The rear suspension will fit in the back of sierra with no seats in, though it did drop the car about 1" at the back. It is now at work in the bay ready for me to start stripping it down before i have to take the impact gun back.

17/04/2011

Since removing the Rear diff i have now stripped it down. I've opened the back of the diff and everything looks very tidy inside. Non of the gears show any sign of wear all the edges of the teeth are still sharp. I cleaned the inside of the diff witrh brakes cleaner to help break down the oil that goes solid on the casing. I also cleaned the out side with a industrial cleaner. it hasn't really cleaned it that well. It would need going over with a wire bruish or grinder wheel. Sinces it's going to be under the car I'll throw on some hammerite just to make it look nice.

I have bought EP90 oil to go in the diff, 1ltr is required. Also i have ordered some rear suspension arm polybushs off ebay. im not sure if im going to remove my arms to fit these. I really need the arms off the car but it means disconnecting the driveshafts at both ends, taking off the brake lines and also disconnecting the handbrake + some other bits.

I might just leave the shocker on the arm disconnect the 2 old bushs off the main suspension support and blow torch the old bushes out. The new poly bushs are seperates and will take about 2 mins to fit.

I haven't decided when i will do this as i'll need the 2 poster ramp at work for a few days while i do this.