Hi guys

I’ve been thinking I really need an LSD in the striker.
It’s a live axle, so not a straightforward(ish) swap like the Sierra axle.

Question is I’ve read quite a few conflicting things about how practical it is doing a diff swap on your own on one of these.
Anyone had any experience who could shed any light?
I’m up for doing it myself but don’t have the lost comprehensive tool set, and don’t really want it taking months to do either...

Any help appreciated
Andy

Swapping the diff is easy, assuming that it's the correct type. Just pull the half-shafts, disconnect the drive shaft, undo the fixing bolts, pull out the diff assembly*. Re-assembly is the reverse, as they say in Haynes manuals. Far easier when the axle is out of the car!

Rebuilding the diff assembly itself is a totally different matter...

* and drain the diff oil before you start (guess who ended up covering his slippers with smelly diff oil).

[Edited on 21/12/17 by David Jenkins]

Been looking into this for my anglia.

Basically two types, plated and auto torque biasing (ATB). Plated good on track but need special gear and occasional set up plus need to decide on ramp angles on and off power plus preload. Atb potentially better for road, standard gear oil plus fit and forget but does not fully lock if one wheel is off the ground.

Plated include the original Salisbury, quaife, tranx and 3j.
For atb there are the pukka quaife ones or there are some newer Chinese copies badged black line at half the price.

Worth keeping an eye out on turbo sport forum, these come up occasionally, a quaife atb with bearing just went for £400.

[Edited on 21/12/17 by Ugg10]

Thanks, now when we talk about a diff “assembly”, what exactly are we referring to?
I’m assuming it’s a bit more than just buying a new lsd that replaces the existing open diff and that I would essentially need to strip a load of bits off the old assembly to refit with the new lsd?

Hi

Put, or rather had put in, a Quaife ATB into my live axle Striker.

Totally transformed the car - on the track and on the road.

Plate diff's in a car this light are questionable IMHO, probably when perfectly set up for the conditions on 'that' particular day they may be a tiny bit quicker.. but for the vast majority of the time an ATB will do the job.
Certainly when we won the midland speed championship with the Striker we didn't feel the need to have a plate diff in it..

It's now been in the car, untouched, for around 8 years or so and with considerable track mileage too.

As long as you have no boot section floor / diffuser in the way, should be doable with the axle in the car I reckon, as long as you're working on it from underneath, otherwise it's probably not too bad if you take the rear body section off - though once that's out of the way you could have the axle out and on a bench in about half an hour!

I've fitted one of the Blackline ATB diffs to my Locost and as mentioned above, removal and replacement is the easy bit. The Haynes manual gets to the bit once the diff is out of the axle and then says take to a specialist!

The diff set up looks a bit daunting at first but having bought a replacement bearing set, it came with instructions on how to set backlash and pre-load on the pinion. Before I stripped the open diff, I took measurements from the rear face of the diff to the housing so I had somewhere to aim for when putting the lsd back in.

To set the backlash, I used a dti with a magnetic clamp to check the amount of movement in the crownwheel when rocking the pinion. The idea is you check this measurement in 3 locations on the crownwheel and once happy with the setting, tighten the clamps to hold it all in place. To check it all meshes properly, use Engineer's blue to leave a trace and readjust if needed.

I have to say, I spent 3 evenings making sure I'd done it right! The dti, magnetic clamp and engineer's blue all came from ebay at under £20 for the lot. Ultimate accuracy from the dti is not a concern as you are only looking for the difference in movement to determine the backlash.

The Blackline diff looks really nicely made but I haven't driven it yet, so time will tell. I have no mechanical training, but have built competition cars over the years and this time I decided to do everything myself, so learning lots of new skills like spray painting, setting diffs, wiring etc. Take time and read all you can, but get stuck in!

Hope this helps.

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Originally posted by pekwah1
Thanks, now when we talk about a diff “assembly”, what exactly are we referring to?
I’m assuming it’s a bit more than just buying a new lsd that replaces the existing open diff and that I would essentially need to strip a load of bits off the old assembly to refit with the new lsd?

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I've had a quaife atb for about 11 years, it definitely improved the traction out of corners without any adverse effects.
I bought it as a second hand diff unit. About 3 years in, the crownwheel picked up and left an unrepairable mark in a tooth which made it sound horrendous.
I bought a good s/h crownwheel/pinion and built it into the diff housing, I also stripped and cleaned the atb unit as there was a good chance that some of the picked up material could have ended up in there. I did find some pickup on a couple thrust washers in the atb that i planished off and the refitted with the washer flipped over, the rest of the atb was in good condition.

As you'll only be replacing the open diff with an atb, you won't be affecting the pinion position/preload at all, which is the hardest bit to get right when fitting a new or second hand cwp.
The things to get set right are:
With the diff/crownwheel removed, check the pinion drag using a spring balance and some string around the flange - calculate this torque as inch pounds - this figure will be used later.
0.15mm +-0.02 crownwheel backlash, if you check the mesh pattern before and after with engineers blue you can match the wear pattern to the original to keep the diff quiet, if it is installed to the spec but not meshing as originally installed it may be harsh under acceleration/overrun until bedded in in the new position and susceptible to picking up and damaging the crownwheel.
0.22mm cap spread with the bearing side adjusters correctly tightened, as you tighten the caps it will affect the backlash - you may have to slacken one and reapply the load to the other to trim the backlash once under load.
Once fitted to the given figures, recheck the pinion drag, it should be 6-12 inch pounds higher than just the pinion - with new pinion bearings and a new oil seal the total figure should be 20-26 inch pounds - with bedded in/used pinion bearings the total should be a reasonable amount lower.
This torque should not vary during the rotation of the flange, if it is tight at any point then further investigation will be required.

One thing to note is the clamping force of the pinion nut against the crush tube is marginal (when driven hard) at retaining the drive flange - this can be noticed by a clack/clunk when going from reverse acceleration to forwards acceleration. I had this with the original diff in my car after about a year on the road, and it was slightly present when i replaced the cwp on the atb diff.
If you have this occuring at present removing the crush tube and getting a solid tube turned up of the same length to replace it will allow you to fully torque the flange nut up to increase the clamping force.
It's also possible to loctite the splines of the drive flange to take up the slack tolerances and refit exactly as removed, but it does make removing the flange in the future difficult.
The crush tube replacement part can be reused until the pinion bearings require replacement, as its length is specific to the bearings and diff housing.

IIRC i have an escort haynes manual that actually has the procedure detailed, i'll try and upload some photos.

Dave

Thanks all,

So I know we’re biased on this forum but the general opinion then is that I should do it myself?
Still not sure I feel 100% confident about it, but definitely want an LSD, just trying to work out whether I should do it myself or pay someone to do it...

I would think you're looking at £120 in labour for a specialist to build up your existing diff assembly with a new atb diff.

You should be able to do this yourself providing you have the following:

A decent workbench and vice to handle the diff, in a clean as possible enviroment.
Something in which to clean components with paraffin, and compressed air to clean/dry afterwards.
Plenty of lint free cloth to clean up the pinion teeth, and where engineers blue has been used.
Access to:
-A dti with either a magnetic or bolt down stand.
-A spring balance 1-25lb should be ok, or metric equiv if you don't mind converting units.
-Digital verniers or micrometer large enough to measure the bearing cap spread (can be measured internally or externally).
-A suitable torque wrench for the crownwheel and cap bolts.
-Either the special tool for the bearing adjusters, a face pin spanner or a large pair of circlip pliers.
Clean fresh gear oil where required durng assembly.

The only other thing required is time without distraction to work methodically through the procedure.

If there is any spalling on the diff side bearings surfaces when disassembled (this won't necessarily have manifested as a noise unless spalled to the extent of pitting), it would be recommended to replace all bearings within the diff which will add £50-70 to your parts spend and would require the pinion to be setup as well.
It is quite likely if you get the diff done by a specialist, they may want to replace these bearings anyway to cover themselves.

If you end up buying a pre built up diff, then it's just installation with a new gasket, there should be no problems here.
IIRC the diff unit will go in and out in situ if the lower arms and panhard rod are unbolted and the axle rotated towards the rear to clear the tunnel, assuming your brake hoses etc have enough free movement.

Dave

Thanks, that’s quite helpful, maybe I should have asked for a tool list to begin with! I don’t think I probably only have maybe half of that stuff, £120 isn’t that bad so maybe I should just give it to someone with the right tools and know how to get it done!

You will also find a slide hammer to remove the drift shafts useful ,also allow space for me using it and enough to at least ease the shafts out of the axle casing far enough to remove the diff .

quote:

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Originally posted by Andrewm
I've fitted one of the Blackline ATB diffs to my Locost .....

The Blackline diff looks really nicely made but I haven't driven it yet, so time will tell.....

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I've attached the haynes manual sections relating to english diff overhaul, there are a few omissions but combined with what i've already posted should cover everything.

https://www.dropbox.com/sh/k9y2ymlb7st6u0p/AADkqAIEd1R0icuWR8sAIY1wa?dl=0

I'll add the torque specs section at some point.

Dave