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gearbox oil

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Woodie

Woodie

Jedi Warrior
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WHen I got the car on the road on june 30, I filled an empty gearbox with hypoid 90 oil. Based on what I have been reading this was a mistake. How corrosive to the workings of the gearbox is this oil, how soon should I change out and when I change it out for 20w50 do I need to flush the gearbox with something ?? or just run it get it warm and then drain and change??
 
Heh, should shift a bit better as well Woodie.
 
actually it has been shifting quite well, not even stiff on the past few cool mornings (shifting, not me !!!)
 
Hmmmm, it is going to get better.
 
Or, if the 90wt made it smooth, wen you go to 20W50, you might find its sloppy (read "worn")....but you need to get that 90wt out.
 
Why does he need to get rid of the 90wt and put in 20/50??
I must have missed something,as I've 90wt in my gearbox too.

Stuart. /ubbthreads/images/graemlins/cheers.gif
 
I had done some research on gear oil and found that GL5 is supposed to be corrosive to brass and copper. Seemingly GL4 is the only way to go. That being said in one of my cars right now I'm using a 20-50 RedLine racing oil. It has no detergents or organic additives (acids). I'm very pleased with it.
If you read the fine print on most gear oils now a days they are ALL GL5.
/ubbthreads/images/graemlins/nonono.gif
 
Apparently hypoid gear oil is corrosive to the brass parts in the gearbox. I do not know how long it takes to affect the metal, I have had mine filled since mid june...and will now change this weekend.
 
Stuart,

The 1500 tran takes 90wt. but the 1275 tran takes 20/50. For your car, stick with the 90wt.

BTW, the Haynes manual reccomends Hypoid for the tran and differential on the 1500. That is what I have in mine. Should I change it out?
 
If you look in your owner manual, it specifies the same oil for the engine is used in the transmission.
 
Tony,

Do you mean 1500 guys should use 20/50? The Haynes manual says 90wt. If so, it wouldn't be the first time Haynes has steered me wrong.
 
948, 1098, 1275, smoothcase, ribcase, what ever you want to call them, use 20/50
1500, rubber bumper, etc, use 90wt
 
No, 1500's are weird setups (IMHO)...they do use 90wt...he has a 1970 Midget so 20W50.
 
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