I've got a 203/205 doubler with a NWF adapter and the 205 is clocked up I think 1.5" or 2". I haven't been able to drive it for more than a few miles because of fueling issues. Fixed all that and tried to put some miles on it today. Drove about 5 miles and the 203 started puking the fluid. I'm running ATF because I have that weird 205 with syncros. Should I run 80/90 in the 203? Also, the 203 gets so hot that you can barely touch it, but the 205 you can hold onto it and it's just warm. Is that normal?
CK5
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Doubler guys, I've got some questions
- Thread starter 85 Jimmy
- Start date
I’ve never checked the temp of my stuff but I run 80/90 throughout and haven’t had any puking problems. That said, my tcase vents are tied together and run forward to the engine bay so it would have to push a long way to show.
Mine go all the way up the trans dipstick tube
Complete 203’s run motor oil or gear oil depending on part or full time configuration, maybe the ATF is too thin? Although the 205 kinda kills that theory.
Or maybe the 205 copes with ATF better because it oils better than the stand alone 203 range box?
What fluids?
What fluid for the 205, and magnum underdrive are you guys running? Also what in the dana 60 and 14 bolt? I'm going to replace all fluids, need oil and radiator fluid, brake fluid, what power steering fluid,? Synthetic?
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I don’t know, the “maybe” in my post indicates speculation. It’s been forever since mine was only partially apart and I’m not studying it tonight.
I was trying to help you answer this question and I thought Stephen had a good take on it, although a 203 is not mentioned.
Synchro's or not, the 205 has big steel gears, which need the lubricating viscosity of gear oil.
IMHO
IMHO
It’s just not enough atf. Put in high quality gear oil that doesn’t generate a lot of heat and it will be good.
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ATF was spec’d for both syncro’d and non syncro’d at one time or another. It may not be the best but it’ll work.
I’m not selling the idea of using ATF, just stating a fact.
I’m not selling the idea of using ATF, just stating a fact.
I guess while I'm doing fluid changes, I can change the vent hoses, incase a dirt dauber made a nest in them from sitting for years.
I'm only using ATF because I read that the syncro'd versions required it
I'm only using ATF because I read that the syncro'd versions required it
I had a syncro 205 in a 83 K-3500 and I changed to 140 weight gear oil and all was well.
Ran the heavy stuff for about five years and never had any shifting issues and the oil looked great each time it was drained and changed ( oil was changed often since we drove in the swamp most of the time - that water got DEEP at times ).
The thick stuff might give an issue in colder climates with the syncro style shift mechanism but down here in the Deep South it never gave an issue so your 80 weight oil should be fine.
I agree with others that stated above that the thicker gear oil film gives far greater barrier protection to the gears , bushings and bearings and helps keep temps down.
Every type of oil has it’s place but GM was most likely more concerned with ease of the syncro‘d 205’s ability to shift extremely well in any type of climate and went with ATF’s damn near 10 weight viscosity instead of oil with better long term effects and a notchy shifter feel on those K-30’s with auto locking hubs in the mid-eighties.
Thank God that option faded away !
85JIMMY,
John and I were B.S.’n about your issue and had a thought that ties in your overflow and range box only heat problems - could it be that your seal between the trans and range box is shot and the trans is puking hot ATF into the R/B therefore causing the heat transfer and spewing out the vent.
Ya’ might want to check the fluid level of the trans to help narrow this issue down ?
This was/is fairly common when I worked at a trans shop - it’s worth considering.
Ya’ could also measure the amount of fluid that comes out of the RB v/s what it takes to fill it to give an indicator if it’s gaining any.
If it is not getting any fluid pushed/leaked past the seal the RB fluid level should be low since it has puked and spewed some externally already but if it is level or above then there’s your indicator that it’s gaining fluid. Just a thought …
