Speedometer / Transfer case question

[Dymers]

Hello !
I'm a new owner of a 1981 Eagle SX4 with a manual transmission. I have a question : my speedometer was not working but I tested the cluster and it's ok. I removed the cable adaptor to the transmission and I will change it for a new one. But I don't know which kind of oil goes inside ( I see this little plate besides the hole that's written ''use 10w30 engine oil'') and I don't know how to fill it once the adaptor in place. Do you have any tips ??

Thanks !

[rmick]

On the side of the transmission is a plug about halfway up the side. remove the plug and fill fluid there fill to spill.

[eaglefreek]

Here's a pic to help. This is not an Eagle transfer case, just using the pic off the net for reference. I believe at first 10w30 was specified for the transfer cases, than that was changed to Dexron. If you have 10w30 I think I would stick with that. I'd hate to put in a different type of oil after 30+ years. With the vehicle level, you add oil to the fill plug until in drips out. I use a fluid transfer pump that I bought at the auto parts store.

[carnuck]

I run synthetic ATF in mine because of it's anti-wear additives. Not very expensive in the long run.

[eaglebeek]

It's not necessary to put oil in the speedometer hole. Install your cable in the hole...lining up the lugs on the retainer with the slots on the cable...and then fill the transfer case. Lubricant will make its way back to the speedometer gears the first time you drive it.

[Dymers]

Thanks for your help !! I think it was a 10w30 oil inside transfer case. Can I drain it completely and fill up with another oil (maybe synthetic oil ) without oil contamination ?

[eaglefreek]

Yes you can. But take into consideration when seals have a certain oil on them for several years and you introduce a different type of oil, there can be leaks. Transfer case are pretty simple. As long as you don't put some thick gear oil in them, anything will work fine.

[carnuck]

ATF is like 5W30 motor oil except it has a much higher detergent.

[shanebo]

I'll second that comment about going from one oil to another.  I switched to all synthetic lubricants on my car once and I'll be darned if every gasket didn't start puking like it had bad case of salmonella poisoning. Old cars don't like change and seem to get stuck in their ways.

[carnuck]

I switched my Comanche from 10W40 to 15W40 then to synthetic 15W50 (Napa) and it stopped leaking, burning and cut blowby almost totally.

[Dymers]

Thanks for your help !!