IRS & Diff Rebuild with painting - What process / finish is best / correct ?

[Nickleback]

I'm just starting to research what's best paint wise for a complete IRS rebuild & diff change later this year, it seems to me there are several options but all start with complete stripping & blasting, but then what ?

I have done a search on previous threads but opinion seems to be mixed ? So do you -
1.) What was the factory finish in 1970 on a S2, is it best to revert to this or
2.) Epoxy primer & powder coating or
3.) Epoxy primer, anti-rust paint (POR15), then Gloss or Satin black top coat or
4.) Red oxide, then Gloss or Satin black top coat or
5.) Should the diff case be painted differently, looks like a red oxide finish & the cage black like I have seen on some top end rebuilds.
6.) What items should be plated and with what finish.

& finally what parts should be always be changed out for new when doing this ?

Rebuild of the rear differential from XKE 3.54 to 3.07 UK specification using different Crown Wheel &
Pinion with existing carrier and LSD rebuilt.
Blasting and powder coating of components ?
Plating of all handbrake mechanisms ?
Full rebuild of hubs including new bearings & seals
Full rebuild of brake callipers with pads
New universal joints
New brake lines
What should be the mandatory upgrades whilst it is all apart ?



PS: I will not be doing the work myself but getting a specialist to complete, hopefully to the right specification as there are different options available.

[abowie]

What I do for a ground up rebuild.

Strip the whole unit to components.
I send the whole diff pumpkin off to be rebuilt professionally. Unless your'e trained to di it trying to rebuild and set up a diff is a losing prospect any day of the week. They sandblast the casing and spray it with enamel paint externally. You can't see it; it doesn't matter if it's not perfect.
Sandblast everything else first.
Powder coat the cage, baseplate and lower wishbones and the 4 springs.
Zinc plate all the nuts and bolts, the hubs, the brake parts including the handbrake controller and the caliper mounting brackets. The bolts holding these are tricky because they also hold the drive shaft bearing housing in place. Again you can't see them and the boys usually just sandblast them and paint the heads silver.
I tend to put the internal handbrake adjuster bits aside in a baggie and not plate them as you can't see them and if they get lost at the platers it's a pita. If you plate the inner handbrake arm cover the captive nut may dissolve. This is easy to fix with a 5mm Nutsert; fits the 3/16 setscrew perfectly.
I just sandblast all the fulcrum pins. Don't plate them as their diameter is critical within the bearings etc.
The two fulcrum pin brackets get spray can painted. Don't powder coat them.
I spray paint the driveshafts with a can once assembled with unis fitted, as trying to clean powder coat out to fit uni joints is soul destroying, never mind the splines.
Personally I bin all hard brake pipes and brake cylinders, but if your car is running you can reuse these. Obviously replace all friction linings and soft pipes.
I bin shocks and IRS mounts. On NO ACCOUNT throw out or replace the shock springs; you can't replace them without getting them made.
The radius arms I have sandblasted and replace the bushes. While powdercoat is an attractive option for the you need to balance this against the difficulty of getting powder coat in the bush recesses and having to clean it out. I etch them and paint them once the bushes are renewed. If yours are damaged from collision or previous jacking seriously consider buying new ones; it may be the most economical option.
I have undoubtedly forgotten something.

[mgcjag]

Do the handbrake mod while its out....and check out the fuel line...you can only get to it if the IRS is out..so if its pitted/corroded replace it

[JagWaugh]

In terms of upgrades:

Late XJ calipers:
Dust seals are better, but check that they actually fit on the pumpkin before you have them plated. There is a web on the earlier diffs which interferes, so you need to grind away a small part of the caliper to get them to fit. I fit Stainless pistons.

Outer Fulcrum seals:
You can fit a modern lip seal rather than the original felt ones (no mods to the carrier necessary). National 471652, Timken: (CR) 11123 ID:1-1/8 OD: 1-5/8 L:1/4

Fit a Vent and Zerk for the bearing in the hub:



Remote Bleeders:
Either DIY, or purchased.

Add a tow eye:
Either a bracket under a rear shock nut, or weld an eye onto the bottom of the tie plate.

None of these are really necessary.

[Nickleback]

Thanks Andrew,
That gives a good working plan using a combination of practical finishes rather than go the complete powder coat route on everything. Good point about the shock springs as I didn't know that !

It seems that in terms of upgrades there is not a lot to do apart from mod the handbrake compensator, change the pads to greenstuff & possibly install a remote bleed kit.

Check the fuel line whilst the IRS is out is a good point too as I know mine is original

[mgcjag]

Hi Mike....what's the rear ride height..measure it now befor you start....re the rear springs..many have replaced them with no problems ...SNG do a ready assembled spring/shock....I have them and a few friends are using them....boge shocks...and we all have the correct ride height

[mark10337]

In terms of upgrades:
Fit a Vent and Zerk for the bearing in the hub:

I understood everything you mention apart from the Vent and Zerk. Is that some sort of extension for the grease nipple hidden under the journal covers?

[JagWaugh]

In terms of upgrades:
Fit a Vent and Zerk for the bearing in the hub:

I understood everything you mention apart from the Vent and Zerk. Is that some sort of extension for the grease nipple hidden under the journal covers?

Mark,

No, the zerk under the journal covers is just for the U/J. The vent and zerk I'm talking about is to allow greasing the wheel bearings. Originally it was just a cap on the upper surface of the hub carrier. I don't like pry off caps in general, and have always felt that regardless of how carefully you clean the area around the cap, there will always be a risk of allowing some grit into your bearings.

All I did was turn up some "t" shaped hats with a threaded hole for the vent fittings - these go in the original bore where the cap was, and I drilled and tapped a hole for a zerk at a mirror image to where the cap was. You don't have to make a turned hat, you could just weld or braze a suitable nut onto the existing cap. The important thing is that the chamber has a vent to atmospheric pressure. Without a vent, any pressure change in the chamber (pumping grease, heat expansion/contraction, air pressure changes) will either push clean grease past the seals, or suck dirty into them.

This was quick and cheap, doesn't weaken the hub, and makes greasing the wheel bearings just as fast and simple as every other grease point on the car.

[Nickleback]

Steve,
The ride height on the rear of mine looks fine but I will check it as I have just fitted new wheels and you never know ?

I know it has been discussed before, but with an S2 FHC (not 2+2) what is the correct std ride height and where should this be measured from and to ?

[mgcjag]

Hi Mike...there is no measurement for the rear.....however this has come up before and in one post a few members listed there height....measurement was taken from the lowest point on the lip of the irs baseplate to ground.....my 2+2 was 7 1/4ln with 185 65 vrederstiens.......others had 7 1/2 in or about. so around this figure is what your looking fore.....there is no adjustment on the rear unless you start using spacers...ideally set up your front and with a spirit level on the door sill it should be level....

[Nickleback]

Hi Steve,
Just measured the rear and it is sitting at 8 1/4" & the door sill level is slightly higher towards the rear of the car.
So do I leave it as is, or try and adjust it - if so I can only look for spacers when it is taken apart and remove them to lower it slightly ?

[mgcjag]

Hi Mike...it's possibly a bit higher than most.....but at least you now have a measurement....when you strip the irs you can look at what's there....possibly spacers been added or shocks with higher pearches (the length between the spring seat and shock eye)..tyres and pressure will also affect height.....look at as many others to compare with yours and see what u think