Stock diff strength (413)

[Big_P]

Since the spider gears in my differential decided to take a vacation last month in my 86 600ES, I'm kind of paranoid that the replacement transmission (which I'm getting through Cindy ) will suffer the same fate. The car is a 2.2 TII converted and intercooled, all stock except for 14lbs boost.

I plan on racing it once in a while and I enjoy a powerbrake burnout on occasion. Should I be worried? Is there something I can have done that can strengthen the differential?

[turbovanman²]

Get the diff pin savers or EAR's-that's what they look like. Dealer or tranny shops, they stop the pin from coming out but won't stop the spider gear damage from one tire burnout's. The only fix is a LSD or try to balance the front weight distribution and/or shim the sway bar per TDG.

[thedon809]

The 87+ autos have beefier differentials and axles. Don't know how much of a difference it would make if you are killing spider gears. Make sure you flush your tranny cooler and buy a new torque converter when you put the new tranny in. Metal is near impossible to get out of the TC.

[turbovanman²]

The 87+ autos have beefier differentials and axles. Don't know how much of a difference it would make if you are killing spider gears. Make sure you flush your tranny cooler and buy a new torque converter when you put the new tranny in. Metal is near impossible to get out of the TC.

Not much difference for the internals, aka spider gears.

Agreed, also run an external magnetic filter on the cooler inlet. To help with friction reduction, run a litre of synthetic 5w30.

[Speedeuphoria]

I like 15w50

[turbovanman²]

I like 15w50

Ok, there you go,

[Speedeuphoria]

But I'm going to try some tractor fluid this year, not the universal tractor, not sure if i will pay the $$$ for the John Deere or not but there is another tractor fluid at advance auto parts in a 5gal pail thats similar I think.

[Big_P]

89+ has a beefier diff?

I'm aiming for 18-20lbs boost tops, not looking for any serious power. But I do want something that isn't going to shatter when I brake boost like my last one did.

[Speedeuphoria]

89+ has a beefier diff?

just the larger bearing on one side iirc

the spiders are still going to be weak. The diff pin savers will save the case from being vented but the spider gears can still get chewed up

When ohiorob was using the open diff he had to put new spider gears in every 3 races or so or they would go. Of course he was running 500hp but the spiders will always be a weak point

For 18-20lbs just getting the pin savers to save the case, put some oil in with the tranny fluid and the open diff should last a quite awhile

[turbovanman²]

just the larger bearing on one side iirc

the spiders are still going to be weak. The diff pin savers will save the case from being vented but the spider gears can still get chewed up

When ohiorob was using the open diff he had to put new spider gears in every 3 races or so or they would go. Of course he was running 500hp but the spiders will always be a weak point

For 18-20lbs just getting the pin savers to save the case, put some oil in with the tranny fluid and the open diff should last a quite awhile

The larger bearing only came on the Neon trans, IIRC, but as you and I both have said, it won't stop killing the spider gears. Only 2 wheel burnouts or an LSD will cure that.

[TheCanadian007]

In regards to adding motor oil to the auto tranny, what viscosity do you recommend and how much?

[Speedeuphoria]

1 liter or 1 quart, synthetic not sure if the viscosity matters much but anything from 5w30 to 15w50

[shadow88]

Just a little FYI.....If you get the pin retainers, the only real way to tell if they're buggered up is maybe a little noise, but mostly, the amount of movement when the vehicle is in park. It's important to measure the movement in park as a reference when it's first installed in the car.

[turbovanman²]

Just a little FYI.....If you get the pin retainers, the only real way to tell if they're buggered up is maybe a little noise, but mostly, the amount of movement when the vehicle is in park. It's important to measure the movement in park as a reference when it's first installed in the car.

That's a good tip.

[contraption22]

Avoid burnouts. No miracle lubricant, no "diff savers", no tool-steel spider shaft, nothing, will keep the spider gears from welding themselves to the spider shaft with excessive differential speeds.

[Vigo]

The pic is terrible quality but im thinking the pin wasnt the issue here. It seems like the spider gear just broke. A loose fit on the pin could cause that, but so could loose gear mesh due to wear.

How bout some quality pics to assuage my curiosity?

[turbovanman²]

The pic is terrible quality but im thinking the pin wasnt the issue here. It seems like the spider gear just broke. A loose fit on the pin could cause that, but so could loose gear mesh due to wear.

How bout some quality pics to assuage my curiosity?

That pic pretty well tells the story,

[Keito]

Avoid burnouts. No miracle lubricant, no "diff savers", no tool-steel spider shaft, nothing, will keep the spider gears from welding themselves to the spider shaft with excessive differential speeds.

I always remember you saying this a few years back and I never do big burnouts on my GLHT.
Hooks with slicks just fine without it, 1.8xx 60's.

[contraption22]

I always remember you saying this a few years back and I never do big burnouts on my GLHT.
Hooks with slicks just fine without it, 1.8xx 60's.

Yes, and to this day, my best 60ft's have been with no burnout. Just a dry hop to clean the slicks. 1.7x before the Peloquin, consistent 1.6x with the Peloquin.

[John B]

How is Amsoil trans fluid in a 413?