I bring teh dumb.... 700R4 question

[jonrpick]

So, right before I moved my K5 the last time, I decided to top off the fluids, as I was told the transfer case and axle were low. If you've read anything else I went through with this truck, you'll know that I received a lot of bad advice in the past, hence my decision to become a member here...

Anyway, I topped off the transfer case with 85W gear oil. Stupid assumption on my part.

So, don't the 700R4 and NP208 share the same fluid? I know the case uses ATF as well (now I do...). The truck was driven about <200 miles and then shut off where it now sits.

Will flushing the tranny really good clear out all of the 85W? Do you think I did any damage?

 

[reddog64]

does it still move?

If so, take it to the jiffy lube... the one down the road here uses a tranny flush machine that hooks up to your cooler lines and replaces ALL the fluid with new fluid...

I'd do it 2x....

 

[jonrpick]

does it still move?

If so, take it to the jiffy lube... the one down the road here uses a tranny flush machine that hooks up to your cooler lines and replaces ALL the fluid with new fluid...

I'd do it 2x....

Yeah, it moved fine. No slippage or weird shifting.

 

[BGKYK5]

They use the same fluid (ATF) but shouldn't share it unless there is a bad seal between them. If you only put gear oil in the t-case, I'd drain and refill the T-case with ATF, drive it around a while (maybe a couple days), then drain and refill again. There shouldn't be gear oil in the tranny. It'll prolly be fine.

 

[reddog64]

i thought they shared.. but it makes more sence they dont...

If they dont share just do what he said.. drain and fill...
maybe drain and fill one more time after soem driving to clean it out?

 

[jonrpick]

They use the same fluid (ATF) but shouldn't share it unless there is a bad seal between them. If you only put gear oil in the t-case, I'd drain and refill the T-case with ATF, drive it around a while (maybe a couple days), then drain and refill again. There shouldn't be gear oil in the tranny. It'll prolly be fine.

i thought they shared.. but it makes more sence they dont...

If they dont share just do what he said.. drain and fill...
maybe drain and fill one more time after soem driving to clean it out?

Well, the guy that told me this (about 30 minutes ago) just dropped off the replacement NP208 (the old one makes BAD noises / grinding) so it's possible that the gear lube is what held it together for the trip home. I wasn't worried about the case, just the recently rebuilt tranny

He's knowledgeable on a lot of stuff, but his GM truck facts were a little off on some stuff. And I didn't really see a way for the fluid to exchange between the two.

So are we in agreement that they do, or do not share/exchange the same fluid???

Edit: for instance, he thought that filling the tranny would also fill the t-case...

 

[NEK5]

So are we in agreement that they do, or do not share/exchange the same fluid???

Edit: for instance, he thought that filling the tranny would also fill the t-case...

They SHOULD NOT share any fluid, unless of course there is a bad seal, as someone already mentioned.

 

[vortec]

They use the same fluid (ATF) but shouldn't share it unless there is a bad seal between them. If you only put gear oil in the t-case, I'd drain and refill the T-case with ATF, drive it around a while (maybe a couple days), then drain and refill again. There shouldn't be gear oil in the tranny. It'll prolly be fine.

x3 - same fluid but different supply. one time i had to pull my slip-yoke on a hill and lost quite a bit of fluid, but the level in the tranny did not drop.

i might try a hand pump to remove as much gear oil as possible, then replace with atf. afaik, they won't have a harmful reaction with each other. i think a flush would be overkill, unless someone knows of a chemical incompatibility between the two.

 

[BGKYK5]

Think of it this way. You can swap T-cases without draining the tranny and vice versa = no fluid exchange.

 

[jonrpick]

x3 - same fluid but different supply. one time i had to pull my slip-yoke on a hill and lost quite a bit of fluid, but the level in the tranny did not drop.

i might try a hand pump to remove as much gear oil as possible, then replace with atf. afaik, they won't have a harmful reaction with each other. i think a flush would be overkill, unless someone knows of a chemical incompatibility between the two.

Ok... well I believe the seal between the two to be fine, so it's probably limited to the 208, which will be swapped out with the one laying on the garage floor.

Looks like I dodged a bullet

Much thanks guys!

 

[dyeager535]

My experience has been that the transmission will pump the transfer case full, not the other way around. Probably simply from moving forward more than rearward, no idea, but even then that's only happening with a bad seal.

 

[Pookster]

most t-cases are just splash lubricated. There are no complex passages and what not. When you take out your old- tcase, you can inspect the seal of the transmission. If it is bad, then replace seal and flush. If it is good, you might just want to replace the seal, just for piece of mind.

 

[habitatxskate]

no they do not share at all. yeah the 208 takes atf

it takes about 3-5 quarts, or something like that.. the trans takes, well it eats a lot a lot.

200 miles? trans is fine, like i said, no sharing, the tcase your going to want to flush refill, drive for a day, then drain and refill with more fluid.

 

[jonrpick]

no they do not share at all. yeah the 208 takes atf

it takes about 3-5 quarts, or something like that.. the trans takes, well it eats a lot a lot.

200 miles? trans is fine, like i said, no sharing, the tcase your going to want to flush refill, drive for a day, then drain and refill with more fluid.

T-case was already FUBAR. I have a rebuilt replacement...

 

[MTChevy]

if you get bored, tear apart that 208 and play around in there. i tear apart transfer cases, trannys all the time at work, all of them the same basically. get an idea of how it works! dont worry bout the tranny.

 

[jonrpick]

if you get bored, tear apart that 208 and play around in there. i tear apart transfer cases, trannys all the time at work, all of them the same basically. get an idea of how it works! dont worry bout the tranny.

That's actually my plan. I got the diff rebuilding video and I think it's great. I'm gonna get the transfer case video as well and rebuild it. Then keep it as a spare or sell it off.

I'm thinking of buying the 700R4 off the guy I bought the 208 from, and rebuilding that too (he only wants like $150 for it).