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Re: When should a gearbox have an oil cooler ?

Posted: Sat Sep 26, 2009 4:55 am
by kevin
Listen to this.. Diff noise
http://www.youtube.com/watch?v=NaKXHP1KXUo

Re: When should a gearbox have an oil cooler ?

Posted: Sat Sep 26, 2009 6:16 am
by MR2 Zig
That sounds like it has no oil at all in it and its a sloppy industrial speed reducer type gearbox....ouch

Re: When should a gearbox have an oil cooler ?

Posted: Sat Sep 26, 2009 11:57 am
by kevin
Yep , that sounds far worse in fourth. Exactly 2.9 litres came out . The pinion also had identical or uniform wear so there was not a specific failure on one tooth. Had the microscope out. Could see barry from my workshop :shock:

Re: When should a gearbox have an oil cooler ?

Posted: Sat Sep 26, 2009 6:13 pm
by ar4me
Raced 2 weeks ago in 100F ambient, and my temps were as foolows:
1. Coolant: 220F
2. Engine oil: 230F
3. Transaxle oil: 230F
This is with sensors and dash gauges, observed during race - not with external infrared measurements after the fact in the pits. I have no plans to add transaxle oil cooler.

I have raced this box for a number of years with Redline 75/90NS, and it still feels like the first day.

My problems is that brand new rear wheel bearings only barely lasted the weekend... :roll: Both now have significant play and need to be replaced again...

Jes

Re: When should a gearbox have an oil cooler ?

Posted: Sun Sep 27, 2009 12:06 am
by Mats
No way I would laugh at that... :?

This is what's called "experience", no?

Re: When should a gearbox have an oil cooler ?

Posted: Sun Sep 27, 2009 12:09 pm
by kevin
I wish i lived in a first world country where you can get the correct oils and information from suppliers and not have to pay huge school fees from info you get from some chap at the track. I dont believe most things i hear at the track but sometimes there are no options . I think Barry and I must go brew some special rhino oil for our LS units here. :idea: Mats you have to laugh at some of the things we do - its so third world but we get there in the end.
Jes those are interesting temps . I know on wheel bearings on front on some race cars they run them loose so they can expand - according to Julians 75 mechanic.
There is some thing very strange on your rear set up as our one car has 280mm rears with huge offset and no issues in three seasons. Normally problem comes in when you heat and bend for camber on dedion - distortion. You need to check circular.
Hopefully i get my oil specs for gearbox that can be imported and compare that of MD's and Jims specs.

Re: When should a gearbox have an oil cooler ?

Posted: Sun Sep 27, 2009 2:24 pm
by MR2 Zig
I talked to a Union 76 lube tech ....he couldn't come up with anything on his own but cross referenced the lubes in the Car Disc manuals to being 80w90 gear oil with a GL5 rating for my non limited slip transaxle ... Union80W90HD GL5 to be exact.

hth,

Re: When should a gearbox have an oil cooler ?

Posted: Sun Sep 27, 2009 3:09 pm
by ar4me
Thanks for pointer Kevin. I will also check origin of bearings when I pull them out - I can just imagine they are Chinese made. Though, I only buy from reputable Alfa parts suppliers, but you never know. New bearings going in are SKF.
Jes

Re: When should a gearbox have an oil cooler ?

Posted: Mon Sep 28, 2009 7:04 am
by Mats
Kevin, obviously you have internet connectivity, so what's the problem.. :)
Just google away on the lubes you have available and you're bound to find something.

And yeah, check bearing seats/cups/holes for roundness. You need a three-legged inside micrometer to do it properly but I guess you can find big issues with regular tools.

Re: When should a gearbox have an oil cooler ?

Posted: Mon Sep 28, 2009 11:33 am
by kevin
Mats, having the internet is one thing but reading carefully is another ie QUOTE MATS '' A normal gearbox oil (FWD transaxle oil for instance) only have cylindrical gears and can run in almost any type of oil, Dextron/ATF for instance. This will destroy a hypoid gearset in a hurry. "
And this is what it did . Google hypoid gears in wikipedia and it explains how critical the oil is for the sliding action in the hypoid gear . Clearly this ATF or other ATF 's dont have these properties.
Mats im going to have to stick your posts on my garage door everytime Im about to do something '' bright ''
There is a foreign company thats set up here (which has stock) called LIQUI MOLY which recomend a Fully Synthetic Gear Oil (GL5) SAE 75w -90. But i will do more research as this is my only company that has options for me at the moment.

Re: When should a gearbox have an oil cooler ?

Posted: Mon Sep 28, 2009 12:20 pm
by Dennis
The serious 75 TS racers here use Castrol 90w140. It's the same oil BMW uses in the diffs for all M models. It can handle the abuse of a 200 hp Ts without an oil cooler. There must be a BMW dealer around?

Re: When should a gearbox have an oil cooler ?

Posted: Tue Sep 29, 2009 9:57 am
by kevin
Dennis, will check it out. Thanks

Re: When should a gearbox have an oil cooler ?

Posted: Tue Sep 29, 2009 12:56 pm
by Mats
I find your lack of faith disturbing.

Re: When should a gearbox have an oil cooler ?

Posted: Wed Sep 30, 2009 12:11 am
by kevin
:idea: :oops: :lol:

Re: When should a gearbox have an oil cooler ?

Posted: Wed Sep 30, 2009 1:26 pm
by kevin
Dennis, Mats i googled 90w140 on the BMW forum and check this out.
http://forums.bimmerforums.com/forum/ar ... 06632.html
Having second thoughts. Mats , yes i know dont believe everything you read but ..