Rear Diff Mount - Failed!

[dcunn]

Re: Rear Diff Mount - Failed!

Peter, F Y I my Hunter boot floor is like yours, with metal plated around the fuel pipes. Love your diff gantry.

Between David Spolton & myself (but mainly him!) we dropped my diff today, using a suitable system of blocks
of wood which gradually got knocked down. Removed the rear part of the propshaft with the diff as we couldn't
get the bolts undone at the front of the diff, now removed with the assistance of the floor to put the tension on
- - dear Marlin, the bolts were more than twice the length needed.

The diff is a 3.62. I understood fom Danny that 3.92 was normal, so this explains the wildly inaccurate speedo !
I guess I will put it back, the performance is good enough for my use and it will give better economy than the 3.92

I have a good used 3.92 on the bench which was planned to be fitted, but interestingly both it and the one on the
car have failed rear supports

Now to deal with the oxymoron called powder coating, and many many hours of fun - how long have I got till Stoneleigh ????


PS my driveshafts are push in type. On the passenger side one it is not possible to remove the brake back plate from the shaft
It does not slide inboard - is this normal ? Will be great fun with derusting.
The drivers side backplate comes off easily, which I though they both should do ?

[CosworthCabrioLee]

Re: Rear Diff Mount - Failed!

Hi dc speak to bob jackson he has some good push in diffs

[dcunn]

Re: Rear Diff Mount - Failed!

Thanks Lee, I'll get mine checked first and then if necc. talk to him

B Rgds...See you at Stoneleigh DC

[greyV8pete]

Re: Rear Diff Mount - Failed!

Yesterday was just one of those days when nothing seemed to go right so is best forgotten. Today I managed to wrestle a piece of 30mm wide x 4mm thick mild steel into a half decent looking U-strap to add reinforcement to my new Billet Machined rear diff carrier. The reasons for doing this are the concerns that I have already aired on my recent general forum post. It may seem an overkill but will at least give me peace of mind.


Photo notes: The U-strap in its unpainted state; Billet machined mount has temp plain nuts and gash washers just to hold it together for the photo; The assembled mock up does not show the final plastic insert under the U and there will be packing shims between the two components to adjust the fit on assembly.

The new diff arrived on Monday but unfortunately after the sandblasting it had been painted silver, which was not to my liking. Today this has been sprayed with Halfords satin matt black and now looks a bit more OE. I will level it up on the bench and fill with oil before fitting it as it will be easier (and one less thing to forget to do!).

The only thing left to do now before reassembly is to decide if I really want the struggle of moving the diff / chassis holes a couple of millimetres further forward or whether to run with the 2 to 3mm estimated clearance that moving the tank back on the new brackets has achieved. I am fairly confident that the polyflex mount is so constrained that fore and aft movement of the diff will be minimal. Peter.

[greyV8pete]

Re: Rear Diff Mount - Failed!

This may be of interest! Check out the two YouTube links on this site to see what diff movement is possible with the standard sierra diff mount and the billet machined type, when simply levered up and down by hand! Peter.

http://passionford.com/forum/general-car-related-discussion/384733-sierra-and-escort-diff-mounts-some-education.html

[greyV8pete]

Re: Rear Diff Mount - Failed!

Well after a slight intermission to finish decorating the kitchen I am back on the case! Today I have successfully elongated the diff support and outrigger holes forward about 3mm. I used a gadget that I have had for years and finally found where I had put it! (In a safe place of course). It is a cross between an 8mm diameter rat's tail file with a twist drill front end. Once you get the knack of which way to bias / pull the drill it removes the metal surprisingly quickly. A dry fit of the new billet machined mount shows about 5mm clearance with the tank at the top cap screw. My tank front is not vertical so the top screw is the closest to the tank and the lower screw is further away. It will be interesting to see what clearance there is once everything is bolted up tight and as far forward as the elongated holes will allow on assembly.

I have also done a minor mod to the jacking gantry, to allow the diff to be tilted back a lot further, so hopefully it will be easier to get the outriggers up over the suspension arms. With a bit of luck the new diff might even be back in by tomorrow evening! Peter.

[greyV8pete]

Re: Rear Diff Mount - Failed!

All bits bolted on to the new diff today. Levelled and filled with oil! Diff now up in place but with plain nuts finger tight only for today. Fingers frozen and brain heading for hibernate so stopped before I broke something! Currently 3mm clearance with tank but tomorrow will rig ratchet clamps to gearbox X-member and pull diff assembly fully forward in the elongated slots, then fully tighten up with nyloc nuts on. Should still result in about 5mm tank to rear mount clearance when finished. Peter.

[Mikejj]

Re: Rear Diff Mount - Failed!

Sounds like you're making progress Pete.

[greyV8pete]

Re: Rear Diff Mount - Failed!

With the garage extension tent rigged but thrashing around wildly in a near gale today the diff is finally in place! As the new billet mount is more rigid than the Sierra rubber one it has showed up an apparent misalignment of the holes inside the rear of the car. If you measure from the holes to the rear body upright there is a 10mm difference! So I felt pretty safe in fettling an extra 3mm further forward on that side to line things up. I have also made up reinforcing plates to cover the fettled holes.

With the whole assembly in place and torqued up there is 7mm clearance between the cap screws and the fuel tank. The polyflex bush is so well constrained I don’t forsee any fore and aft movement but decided to stick a bit of rubber on the tank to show willing! Photos attached. Peter

[greyV8pete]

Re: Rear Diff Mount - Failed!

Well the new 3.38 diff is now fitted using the billet machined rear mount, plus the extra U-strap for “insurance”.


It’s amazing how jobs grow and collect other jobs as they evolve. The following is a final list of all the jobs just completed, all of which were on my “to do sometime” list:

1. Fuel tank straps replaced with stronger items.
2. Rear exhaust hangers uprated and new hangers added at the front of the large front boxes.
3. Silicone sealed “gaps” between rear floor and tunnel.
4. Gearbox oil changed for Difflock Evolution 1 (hopefully to cure the infamous notchy change on these Rover R380 boxes).
5. Grommets fitted to redundant floor holes. Missing when seat runners moved back.
6. Fuel sender flange leak fixed.
7. Fuel sender adjusted (miserable failure!)
8. Filler neck to body Silicone sealed (water leak).

Hopefully road test tomorrow! Peter.

[Mike]

Re: Rear Diff Mount - Failed!

Well the new 3.38 diff is now fitted using the billet machined rear mount, plus the extra U-strap for “insurance”.


It’s amazing how jobs grow and collect other jobs as they evolve. The following is a final list of all the jobs just completed, all of which were on my “to do sometime” list:

1. Fuel tank straps replaced with stronger items.
2. Rear exhaust hangers uprated and new hangers added at the front of the large front boxes.
3. Silicone sealed “gaps” between rear floor and tunnel.
4. Gearbox oil changed for Difflock Evolution 1 (hopefully to cure the infamous notchy change on these Rover R380 boxes).
5. Grommets fitted to redundant floor holes. Missing when seat runners moved back.
6. Fuel sender flange leak fixed.
7. Fuel sender adjusted (miserable failure!)
8. Filler neck to body Silicone sealed (water leak).

Hopefully road test tomorrow! Peter.

Peter
Its a good feeling when you have completed them all!
Looking forward to your report on the new diff support.
Good luck.
Mike

[greyV8pete]

Re: Rear Diff Mount - Failed!

Today I finally sorted the fuel sender at the second attempt (see separate post) refitted the floor plates with rubber seal edges around the filler and vent pipes and went for a test drive. I noticed a very slight transmission “whine” which may be due to the polyflex diff mount, or the second hand diff, or the new geabox oil, so I will ignore this for now.

With the Difflock Evolution 1 oil in the gearbox the gear changes already seem to be easier so that upgrade seems to have been a success. Incidentally that oil is fully synthetic, has the consistency of brake fluid and smells like sewage! Most strange!

The 3.38 diff is a revelation, a bit like having overdrive on all the gears! Much more relaxed cruising but still plenty of torque there with the V8. If you drop down a gear it still goes to warp speed in no time at all so no problems there. I deliberately tried a gear change in the middle of the slight bend that used to produce a bit of a steering twitch with the old L/S diff and no twitch with the new open diff, so pleased with that too.


In top gear at 40mph the tacho reads 2000 RPM. In 5^th gear at 3000 RPM the speedo reads 80MPH. Tomorrow I will hook up the sat nav and verify the actual speedo accuracy. Peter.