Another Borgy diff thread

[Panko 2,480]

Hi guys,

 

So if any of you have been followung the thread on my wagon, you will know for some time now i have been chasing a bad driveline shudder. Taking off, reversing, and down shifting when i dont rev match. I run a T5 5 speed in my XF wagon. I comverted it to manual from auto, so im still running the original 2.77LSD with the T5. Some people dont agree, but i love that combo.

 

Ok, so just today i picked the car up from having a rebuilt box, new clutch, reco flywheel all fitted up to the car. The box has new synchros, new V8 (brass) extension housing bush, seals, bearings. Smooth as, and i can now down shift without rev matching, and it doesnt shudder. BUT, i still have the shudder taking off from a standing start in 1st, and even worse in reverse.

 

SO, the diff is the one and only thing i havent touched in the driveline. Unis have been done. And now new box and clutch.

The noise it makes when shuddering, is like a "clatter", my father who knows a fair bit has suggested the plantery gears could be worn. Could that be a possibility or could the diff just need adjusting and shimming to take some slop out of it?

 

Any help would be awesome. Im going to take the car back to transmission guy to see what he says (Ford specialist) im at a loss with it, and i am a little upset, after all the money i just spent getting the work done, i honestly never thought it could be diff, but there is now no other option.

[gerg 10,871]

Could be soft/broken engine mounts, causing the fan to clip the shroud as the engine moves. Without seeing/hearing for myself, bit hard to pick.

 

Diff planetaries (or spider gears) only work around corners. If taking off in a straight line, they are stationary inside the carrier. You can check for backlash in the spiders by rocking the tailshaft gently back and forth while listening for the take-up in the gears. The initial take-up is the crown/pinion and the next one the spiders. If there's say 1/8 turn on the tailshaft before the second take-up, your spiders are worn. If you pop the hat off the diff, that will give you more of a clue. You can see a little into the window of the carrier onto some gear teeth and see if they're worn/pitted. Metal in the bottom of the housing is another sign.

 

You say it was an auto before, one thing I've noticed is that auto cars tend to wear out spiders more quickly than manuals. I think the constant power-on doesn't give the surface of the teeth any time to take on a fresh film of oil like manuals do between changes. Just a theory... But I digress

 

The only time I've seen a diff cause a shudder is around corners when a cross-shaft has snapped. Crown/pinion wear will just be noisy.

[Panko 2,480]

Ok so in a straight line, its not the spider gears, however i live on a court bowl, and if i turn around in the court in neutral, as its doing the tight turn the diff makes a bit of clunking or rattling noise until i either straighten the car up, or i put it gear and put some load on the diff.

 

It could be engine mounts, again. I replaced them about 18 months ago, chasing the the same issue. It did help, a bit, because they had both snapped, so maybe the shudder has caused them to break again.

[Thom 6,650]

When was the last time the diff oil was changed?

[Panko 2,480]

Probably about 2 years ago. Maybe 20,000kms since doing it. Also added some thickner/conditioner to the oil to try help. It was quiet for a couple months then started again

[winton 399]

Try this additive :-D

[Panko 2,480]

Bahaha i was waiting for someone to say that. Only a matter of time.

[Panko 2,480]

I had the ingenious idea today, or setting up my GoPro on the drive way, and slowly rolling the car back and forth loading it up, to see whats going on under near when the driveline is shuddering. 

what i saw was very interesting. Im not starting to think its the unis. the front uni, vibrates significantly for a couple seconds after initially coming to a dead stop. in the video i can see the yoke is still, but the tailshaft on the other side of the front uni shakes a little until it settles, like the uni is shot. 

Something else i can see in the videos, is the backlash in the diff. When i initially start letting the clutch out, it is clear as day the moment the diff actually takes up, because the tailshaft, instead of rotating smoothly like id expect to see, it "jolts" as the slop in (what i think) the diff finally takes up. I know there is meant to be a certain about of backlash, but for it to be visible in HD footage from under the car, tells me there is too much backlash, or slop in the diff. 

I really can't think of anything else it could be, after the gearbox has just been rebuilt, with new clutch. so i think its down to tail shaft and/or universals, and the diff. I am going to try another tailshaft I'm borrowing off a mate, which is of unknown history, its out of an XG. so process of elimination. wish me luck. 

[deankxf 20,278]

XG will have a different flange to XF , pretty sure the uni joints are different (bigger) also

(assuming your XF diff has the stock diff yoke)(they can be fitted to the XF diff to suit the larger EB XG type)

[Mr Polson 10,214]

Why not upload the videos?

[Panko 2,480]

Hmmm ill have to measure it when i can. I looked at the tail shaft last weekend, it looked identical to mine.

 

Chris, too big of a file. Id have to cut bits out of it, then shrink it, otherwise id be uploading forever lol

[Thom 6,650]

You could try for a 3.08 e series wagon diff, gets you 28 spline and 4 pinion and you can sway any e series lsd into them

[MNTL.XD 3,831]

I'd just replace it all, having new uni's is never going to be a bad thing. They're quite cheap and easy to do and obviously need to be done. With the diff being a 2.77:1 another should be able to be found very easily, they're definitely not a sought after ratio so there's heaps laying around.

[Panko 2,480]

Ideally i want a 2.92. But again i was having trouble finding a disc brake, lsd leaf spring 2.92. If i can find one, ill get it checked out, serviced then put that in the car.

[Panko 2,480]

Can a drum brake diff can be converted to disc brake easily? There are a few 2.92. Diffs LSDs, but drum brake on ebay. There is even one with sway bar mounts which i would go for so i can fit a rear sway bar to my wagon, but again its a drum brake diff.

 

There is always the matter of, if i buy another diff, im obviously goiing to get it done up, but whos to say its not completely stuffed internally?

 

How much should i be paying for a diff from a wreckers? There is one on ebay from a wreckers in melbourne for $150. On top of that i need to get it done up.

[gerg 10,871]

I've been reading up on this too, as I have a 2.92 wagon drum assembly that I want to build up into a 28-spline lsd but i want to use the disc setup already on my car. I think if the axle flanges (what the calliper housing bolts to) sit in the same direction then it's ok, as sedans had the calliper sitting at 6 o'clock whereas utes and wagons have it 90 deg towards the back.

 

You just have to use disc type axle bearings and seals as the alloy caliper housing has a recess where the seal sticks out into.

[Panko 2,480]

Something that Sparky Dave, and my dad both just suggested to me, in seperate conversations, is that part it could the end float in the crank in the engine. Keeping in mind the car was auto up until about 5 years ago.

 

Has anyone heard of this being an issue? Excessive end float in the crank causing this type of problem?

[Thom 6,650]

Something that Sparky Dave, and my dad both just suggested to me, in seperate conversations, is that part it could the end float in the crank in the engine. Keeping in mind the car was auto up until about 5 years ago.

 

 

Has anyone heard of this being an issue? Excessive end float in the crank causing this type of problem?

 

It's actually not too rare in auto 4.0ls as only the xr6 (and 6 cyl ghia) left the factory with a upper and lower thrust bearing and the base models had half of one

[Panko 2,480]

So its plausible, comsidering my engine has never been rebuilt, and has now got 323,000 on the clock.

Is there a way of checking without pulling the engine out and apart?

 

If it is the crank end float, i think i might cry, and the car might end up going on holidays until i can be bothered fixing it

[Thom 6,650]

So its plausible, comsidering my engine has never been rebuilt, and has now got 323,000 on the clock.

 

Is there a way of checking without pulling the engine out and apart?

 

 

If it is the crank end float, i think i might cry, and the car might end up going on holidays until i can be bothered fixing it

 

You can you'll need a crowbar, jack the car up and remove the inspection plate from the bellhousing then set up a dial indicator in the snout of the crank, use the crowbar/ big screwdriver to move the crank back wards against the flywheel, zero the dial indicator then move the crank forward using the inner part of the harmonic balancer and read how much movement you'll have, a workshop manual should be able to tell you the tolerances for crank endplay

[Panko 2,480]

You can you'll need a crowbar, jack the car up and remove the inspection plate from the bellhousing then set up a dial indicator in the snout of the crank, use the crowbar/ big screwdriver to move the crank back wards against the flywheel, zero the dial indicator then move the crank forward using the inner part of the harmonic balancer and read how much movement you'll have, a workshop manual should be able to tell you the tolerances for crank endplay

Ok cheers. Maybe ill give that a shot on the weekend.

 

One last question, because i havent done this before, what do the dial indicators look like? Where am i likely to get one?

[Thom 6,650]

That's a dial indicator, you can get them in metric and imperial, any good tool shop should carry them (total tools, backwoods etc )

[Panko 2,480]

Ok so good and bad news.

 

Today i put the wagon up on stands, put the car in gear, handbrake off and rocked the wheels back and forth, while someone held the trailshaft still. The slop in the diff was way more than we expected. It appears to be mostly in the crown and pinion wheel meshing.

 

I decided to doing a service on it. Dropped the oil, new gasket, oil, and a Penrite LSD specific additive. The result, it has cut the shuddering down by i reckon about 75%. So to me this proves the diff is the issue. Still has a slight shudder because the diff needs rebuilding. But it is smooth now. The axle does not knock when doing tight turns in my court, and i can reverse up my driveway now.