Gearbox Oil

[I heart the SSS]

Hey guys,

Just a quick question on gearbox oils.

The car in question is not a honda, but all gearboxs share the same traits.

Anyway, the gearbox in questionhas done 200,000ks, rather old.

She is currently running on redline 90, and had issues going into and down to second (pretty sure its both) whilst the car is cold ONLY.

also, only at high revs, AKA 6K +

After a half hour / once the oils warmed up and has thinned slightly, she doesn't crunch at all.

In fact, its more of a "forced selection" then a crunch. it makes an odd noise from inside, but it nothing compared to a mis-shift or clutching too early during a change.

Now, i've been told if I run redline 70, the problem will go away, as the oil now is too thick.

What do people think.. I think its new gearbox time / rebuild.

(Car is an MR2)

[dudeling7]

hey man, i think i have a similar problem with you.

only on cold frosty mornings if i change straight into second slowly it will be really tough and crunch sometimes. but then if i do it quickly its alright.

then after about 10 mins of driving its gone. so usually i just double clutch into 2nd till its warmed up and no worries then. doesnt always do it either.

im using honda oem fluid atm.

sorry i couldnt help you.

[JohnL]

whilst the car is cold ONLY.

also, only at high revs, AKA 6K +

You're absolutely crazy to be revving a cold engine to 6,000rpm. Don't do this, you'll damage the engine, and if you don't, then according to your description of the problem, the problem will disappear...

[I heart the SSS]

You're absolutely crazy to be revving a cold engine to 6,000rpm. Don't do this, you'll damage the engine, and if you don't, then according to your description of the problem, the problem will disappear...

Not me, previous owner.

I'm just worried, i really don't want to be pulling a gearbox out of a Mid engined car.

And my dad will give me the shits as him and the boys at work will have to do it.

We'll see what happens, but thanks for the word.

[JohnL]

FWIW, if it were my car I'd ignore the problem until it becomes significantly problematic with the box at operating temp. In the meantime learn how to shift into 2nd without crunching (i.e. be more patient when selecting 2nd, learn to rev match, heel / toe etc).

[PNS 001_EG3]

try the other oil and if i dont work rebuild ya box! hey n im not even a rocket scientist

[PNS 001_EG3]

heel toe has got nuthin to do with selecting a gear in his situation

FWIW, if it were my car I'd ignore the problem until it becomes significantly problematic with the box at operating temp. In the meantime learn how to shift into 2nd without crunching (i.e. be more patient when selecting 2nd, learn to rev match, heel / toe etc).

[string]

Is it an AW11? Both the AW11's I've driven had ****ed up syncro's, especially second gear.

You're shit out of luck, it's never going to get better. Once the metal is worn away, it doesn't come back.

[I heart the SSS]

Is it an AW11? Both the AW11's I've driven had ****ed up syncro's, especially second gear.

You're shit out of luck, it's never going to get better. Once the metal is worn away, it doesn't come back.

Tis

Hence why I said rebuild time, just gotta have the patience to pull it out.

[string]

I feel your pain; I love everything about the AW11 except for working on it.

[I heart the SSS]

Exactly.

It's a good project car, has lots of potential, and my dad has worked on dozens back home.

Just a huge ****ing bitch to work on..

Might buy and sell it however.

[Feverpitched]

If it's not already, then it's GZE time...

Edit: And to answer your question, going to a thinner oil usually improves cold shifts, but may harm warm shifts. The Toyota recommended oil weight is what I'd go for. As a stop-gap, you can use Nulon G70 to smooth out the shifts.

[JohnL]

heel toe has got nuthin to do with selecting a gear in his situation

If the synchromesh is worn then it will help when shifting down from a higher gear, though it may be that double declutching may be needed (like in the old days before cars even had synchromesh). Changing up from 1st the only thing that can be done (short of replacing the synchro) is to wait long enough for the engine rpm to drop to the rpm that matches the gear ratio (lighter flywheel will help with this, allowing rpm to drop faster).

It occurs to me that some gearbox oils are designed for racing gearboxes that don't have synchromesh, and if the particular Redline oil being used is one of those then it may be too slippery to allow the synchro to work effectively.

I know that Motul makes at least two synthetic gearbox oils, one for boxes with synchromesh and one for non synchro racing boxes. Does Redline do this, and has the OP been tempted by words like 'racing' and 'extreme loads' (etc) to use the wrong one?

[I heart the SSS]

I didn't put the oil in, the previous owner has.

It's called "redline 90"

I've heard about redline shockproof or something?

That may help.

[Limbo]

Its a common problem with alot of toyota boxes.
What i have seen work on some is a mix of auto fluid & manual fluid 50/50 mix.
There is also other gearbox addative you can mix with your gbox oil also.

I'd had mixed results from fellow tyomods at the time about redline, some swear by it and some say it made it worse. If you've got the LSD box then make sure you use the LSD version cos there is a difference.

[JohnL]

I didn't put the oil in, the previous owner has.

It's called "redline 90"

I've heard about redline shockproof or something?

That may help.

I'd get in touch with the Redline distributor, or check the Redline website, to see if that's a suitable oil for your box. Redline oils are supposedly as good as it gets (hearsay), but it won't matter if your oil isn't formulated to work with synchromesh boxes.

[Feverpitched]

Yep I'd be real careful about box oil. For example, I know for a fact that some Mazda 'boxes don't like oils with high sulphur content, which ruled out a lot of 'big' name brands for me at the time.

OEM is usually the go unless you do heaps of track work.

[I heart the SSS]

Thanks for the input guys..

We'll see what happens with this car..