Oil Seal-Differential

[Tinster]

My Pedro-ized drive diferential makes great thunking
and clunking sounds when I shift gears. I have purchased
a solid, used TR4A differential. Everything inside rotates
smoothly and quietly. No thunks!!

My existing differential leaked pints of lubricating oil.
It cost me $500. to have new oil seals installed on either
side of the differential.

I am thinking about installing new oil seals in my replacement
differential. I have Bentley but it doesn't have the clarity I
need as a non-mechanic.

Replace oil seals:

Q1- Is this a task that requires specialized tools?
Q2- Are soft washers required at bolt No.1, like when
I changed out my clutch?
Q3- Is the huge nut No2 difficult to remove? Can it be used again?
Q4- Is the ballrace something I need to worry about?

Finally, is this a task a non-mechanic should attempt or should
I bite the bullet and pay another $500. to install new oil seals?

Thanks as always,

dale

 

[TR3driver]

Replace oil seals:

Q1- Is this a task that requires specialized tools?

As I recall, there is a special puller needed to remove the side flanges from their (tapered) shafts, just like with the hubs. Usually they aren't as tight as the hubs, so you might get away with using an ordinary puller, but it's still a risk.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Q2- Are soft washers required at bolt No.1, like when I changed out my clutch?[/QUOTE]The factory didn't use them, so I assume the answer is "No". Worth a try anyway, since it would be easy to add later if needed (unlike the gearbox cover). Or, you could smear a little RTV under the bolt heads before you install them.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Q3- Is the huge nut No2 difficult to remove? Can it be used again? [/QUOTE]Just takes a little creativity to get that much torque on it. ISTR we drilled a length of flat rebar (from Home Depot) to fit two of the bolt holes.

Nylocs lose some of their holding power every time they are removed and installed, so I wouldn't take the chance if I didn't have to. If you do want to reuse it, you can "refresh" them (once) by laying the non-nyloc side on a hard surface (like the floor) and whacking the nyloc side just enough to squeeze out some more of the nylon.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Q4- Is the ballrace something I need to worry about?[/QUOTE]I'd certainly want to inspect the bearing. Any roughness is cause for replacement, IMO.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Finally, is this a task a non-mechanic should attempt or should
I bite the bullet and pay another $500. to install new oil seals?[/QUOTE]Seems to me you've done very well in the past ... might as well tackle this one too !
The only question is how do you know when you've got enough experience to quit calling yourself a "non-mechanic"

 

[TR6oldtimer]

Dale, you may be able to take the sub axles from the old differential (with the new seals) and put them on the new diff with the old seals. All that is involved is removing bolts number 1 and a new gasket set.

 

[2wrench]

Dale: I'd say you have to qualify for at least novice
mechanic level....but mechanic, for sure.
I think you've done quite well and have proven
an inspiration for me.

Wrench on, Bro

 

[Brosky]

Dale,

Do you have any type of a puller to use for the stub axles? If I were you, I'd get that before I started.As well as the new seals and some RTV sealer of course.

Other than that, with your methodical mind and ability to ask a question and get a quick answer when you're not sure about something, you will be fine.

 

[TR6oldtimer]

Paul, there is not a puller made that will pop the hub from the axle stub. Did that, tried that. Finally had a shop do mine, they used an hydraulic press to release them at around 15 tons.

 

[DNK]

Dale- Great timing on that question. On my *8 my flange gasket is leaking and I need to know does the big nut (#2) have to come off or can I just remove the 4 smaller bolts (#1) to get to the gasket. Randall?

 

[Tinster]

So OK! Not a DIY garage project.

This sounds like a project way beyond my capabilities.
I don't feel like shelling out another $500 to have new
seals put into my replacement differential. I think I will
wait until my existing differential totally fails.

If I drive it until it fails, am I in danger of my car
wrecking, flipping over, causing an accident if it fails
at highway speed? Will the differential failure cause
anything else to break apart- like rear axles, wheel hubs,
trailing arms, drive shaft, clutch or tranny, etc.?

Right now it makes a very solid "thunk" sound when I shift
gears. On jackstands, I can hear the thunk inside the
differential when I rotate the wheels back and forth.

d

 

[PeterK]

Sounds like maybe it's the diff mounts and not the diff.

Have you checked the chassis at the diff mounts for cracks and installed a reinforcing kit? Common problem on IRS cars.

 

[TR3driver]

Dale- Great timing on that question. On my *8 my flange gasket is leaking and I need to know does the big nut (#2) have to come off or can I just remove the 4 smaller bolts (#1) to get to the gasket. Randall?

Oops, wait just a minute here ... Isn't the TR8 solid axle like the TR7 ? If so, it doesn't even have those flanges !

So, let me rephrase : on the 4A-6 you can change the gasket by just removing the 4 bolts & the axle/bearing as an assembly.

 

[DNK]

That seems to be where it is leaking.

 

[TR6oldtimer]

So OK! Not a DIY garage project.

This sounds like a project way beyond my capabilities.
I don't feel like shelling out another $500 to have new
seals put into my replacement differential. I think I will
wait until my existing differential totally fails.

If I drive it until it fails, am I in danger of my car
wrecking, flipping over, causing an accident if it fails
at highway speed? Will the differential failure cause
anything else to break apart- like rear axles, wheel hubs,
trailing arms, drive shaft, clutch or tranny, etc.?

Right now it makes a very solid "thunk" sound when I shift
gears. On jackstands, I can hear the thunk inside the
differential when I rotate the wheels back and forth.

d

Dale,
You had the old stub axles taken apart and new seals put in right? So once again, take the stub axles off the old diff and put in the new diff. Simple, just eight bolts and new gaskets and it's done.

 

[Brosky]

Ray,

I had hoped that if Dale just had them off, it would have been easier. But then I realized that when mine were done, it took a press at many tons as well.

My OOPS!!!

EDIT: I found the pictures from that rebuild:

 

[TR3driver]

If I drive it until it fails, am I in danger of my car wrecking, flipping over, causing an accident if it fails at highway speed?

Unlikely IMO. It's marginally possible that something could break and cause one or both rear wheels to lock up, which might cause you to lose control (or more likely around here, get rear-ended).

But I would say that chances are very good it won't actually break anything; and if it does happen, it will be accelerating from a stop in 1st gear (when stress on the diff is highest), when a failure would be relatively harmless.

My TR3A diff was at least as bad as yours (nearly 1/4 turn of one wheel before the other wheel & driveshaft start to turn) when I got the car in 1982 ... it wasn't noticeably worse when the car was wrecked in 2005, over 100,000 miles later. Of course, the full synthetic gear oil helped that, IMO.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Right now it makes a very solid "thunk" sound when I shift gears.[/QUOTE]Smoother driving technique can help reduce that. Try not to change the forces on the differential, by keeping engine rpm up while shifting (engaging the next gear up before the engine slows below the speed it will be turning after you release the clutch).

 

[Tinster]

Getting rear ended sounds bad.

Just this afternoon, I saw a young woman driving a ragged
out, old Chevy Blazer get rear ended right beside me at a
traffic light. The feller driving the red car seemed very
unhappy when he popped out of his car. Had a cell phone
glued to his ear, he did !!

 

[Brosky]

So it's her fault that he's an idiot who has an electronic growth on his ear???

Just keep driving and don't rear end anyone with a camera on your forehead!

I guarantee that it will cost a lot more to fix his than hers.

 

[AweMan]

Sounds like the "Feller" Is/was having a bad day. IF he was actually talking on the phone while driving, he got wayyyyyyy less than he deserved I.M.H.O.! Too bad for the woman tho, but then again, on the brighter side she may get improvements to her Blazer at his expense. Serves him right! It`s probably a good thing i`m not a police officer because I would make it one of my major duties to be on the lookout for driving cell phone users and ..... if I caught them at it, they would not like the outcome.
OH and B.T.W. I know Nothing about that particular differential, other than to say if it is I.R.S. check that the mounts are secure and the universal joints are not worn {as you well know they can create a very noticable clunk} As far as the dis-assembly & re-assembly, I am in the dark. Sorry Dale!

 

[Tinster]

Aweman:

For sure it is the differential that is making "thunk".

The u-joints are all new, the diffy mount bushings all new
and the passenger side, diffy mounting pin box has been
repaired. The tranny mounts are new and the entire rear
suspension is new. The drive shaft was donated by Paul
and checked out by a professional old car mechanic.

The diffy makes "thunking" sounds when it is out of the car
on a workbench.

My replacement differential makes no noises on a workbench.

The guy from whom I bought the replacement differential told
me he did not believe his oil seals leaked.

I am going to have an oil drain plug machined into the casing.
Is there any way to test the oil seals for leakage-
on a workbench?

Maybe I should just install it and see what happens?

d

 

[AweMan]

My best guess is that the backlash between the ring and pinion is more than O.E.M. specs due to wear on the teeth and or bearings and spacers. As far as bench testing for leaks on the newly purchased differential, I myself wouldn`t know of any way to do that. As you know oil becomes more fluid as it gets warm, so you would have to have a way to warm the differential up to operating temp in order to test it. Even then, under normal operation there would be a silght pressure inside of the diffferential, Hence the P.E.T. {Pressure equalisation tube} coming out of the top of most differentials.
I suppose you could drive your car a few miles then I.R.D. gun the differential and note the temp. Then somehow warm the one to be tested to the same temp and turn it on its sides and every other way imaginable to see if any of the seals are leaking. I don`t know {The hardest three words for a man to say ..... Red Green} Just a W.A.G. at an attempt to divise some kind of a test. But then there is the movement factor too, meaning all of the parts inside are spinning at a pretty good clip so I don`t know how you would simulate that condition at the same time.
Your best bet might be to just instal the newly purchased one in the car and hope for the best, in any case you will have one on hand to either rebuild or have rebuilt by someone while you drive the other.
Again i`m probably not the one to give you the best advice here, as I stated I know virtualy nothing about this particular differential.

 

[TR6oldtimer]

Maybe I should just install it and see what happens?

d

Finally a great idea. Put 'er in and go. As for the drain plug, in my opinion, forget about it. If the designers thought one was needed, it would be there. Use a good synthetic oil and drive.

To test the seals on the bench, fill with oil and set it on each side and on the drive flang. It oil comes out the seals are shot.