Replacing front diff mount. Hard to do ?

[aegean]

My 260 auto clunks when I put it into Drive, so I presume it is the front diff mount at fault. I had a look through the forum but couldn't find any reports on anyone having done it, but presume there have been several since this seems to be a common problem. From the workshop manual, it appears to be a rather lengthy  procedure, with some special tools required. I have a sliding hammer, but it also mentions another special tool. Anyone know what it is and if anything else can be used ? I regard myself as reasonable competent at mechanical repairs so how long should I expect this to take ? If anyone has had the job done at a workshop, how much did they charge ? Did Nissan produce any workshop job sheets that document how many hours the job should take ? Are there any other bushes and/or other parts that should be replaced at the same time ?

[zedrally]

Have you checked the half shafts ?

 

You'll get a clunk from them as well if the "U" joints are worn.

 

My money would be on the half shafts....

[aegean]

Thanks. I will check that first.

[twosixty]

My money would be on the half shafts....

 

+1

Grazed knuckles, sore back replacing/upgrading front diff mount and it still has a clunk...bastard

[gilltech]

Ditto I'd look at the unis in the drive shaft & the 1/2 shafts first, too; they'd be the most likely. I don't think the front diff mounts cause trouble, but check the rear diff mounts while you're at it, as in where the diff mounts to the moustache bar - I've had one shear causing the diff to rotate. Or, a clunk could be in the spider gears in the diff - there's a shear pin that can cause trouble, or a diff alignment issue. My 2c worth.

[silverz]

I had to replace the front diff mount on my 240Z as the rubber had split allowing the diff to move and clunk. We also had to rebuild the diff as the bearings were gone and  it wined like crazy.

We attached the new mount to the diff prior to jacking the diff back in position and reattaching the prop shaft and half shafts etc. It was quite simple there was no need for slide hammers etc though maybe 260Z is different?

We fitted a 260Z diff mount on advice from Allzspares where we bought the mount from. Apparently 260Z mounts are stronger.

 

Regards

Peter

[Daedalus-Z]

I just took a look at the rear end of the 260 as it had basically the same issue (as well as a sticky throttle), when driving back from having it's exhaust fitted. Predictably the rear diff mount was stuffed, the strap had no tension and not knowing what it was, I had removed the chain the previous owner had installed as a 'workaround'.

 

There are quite possibly easier/better ways to get the diff mount off, but this was what I ended up doing:

DISCLAIMER: I'm a crappy mechanic! I don't recommend following the below, it's just to give people and idea of what I did that seemed to work.

 

1) Remove exhaust (it blocked the cross-member on my car)

2) Loosen vertical bolts holding diff to mount (17mm I think?). Nuts are were ontop of diff and bolt heads could be reached from the rear of the car. After much contortion I had had them loose. I made sure I loosened all the bolts before removing any of them.

4) Loosen the single bolt in the centre of the cross-member that hold the diff mount down. (circular cut-out in the middle of the cross-member, easy!)

3) Support rear suspension arms and the diff. (I used 3 old screw jacks) This cross-member also seems to hold the arms in place, so it seemed sensible to support them... what with the wheels being off the ground and all. Obviously the diff is heavy and should be supported.

5) Loosen the 4 bolts that hold the cross-member to the body (14mm I think?)

6) At this point you can undo the all of bolts in any order you see fit. Keep in mind: if the diff mount if stuff like mine was, when you undo the bolts holding the cross-member to the body, the mount will fall apart and if you aren't ready the cross-member will drop onto you. When you fully undo the nuts ontop of the diff, the bolts will be able to slide down and you should be able to remove the top of the mount.

 

Voila! The diff mount is on the ground and attached to the car! It's super hard... but it does involve a lot of jacks...

 

You possibly can also remove the diff strap at this point if you want to replace it, the side mounts are accessible (sort of) beside the diff.

 

I'm waiting for paint to dry on the cross-member, but I'm hoping installation will simply be the above reversed!