TheSamba.com Forums
 
  View original topic: Transmission Cooler flow Page: 1, 2  Next
James 93SLC Mon Jul 30, 2012 10:59 am

Hooking up my external transmission cooler with a thermostat and getting ready to hook up the hoses.

Anyone know which port on the back of the trans is the output and which is return?

Thanks! 8)

**************
Moderator edit: Since conflicting info was posted in this topic, here is the answer based on cooler removal:

Bottom = outlet/send

Top = inlet/return

AtlasShrugged Mon Jul 30, 2012 2:27 pm

Bottom fitting is the ATF pressure outlet..top fitting is the inlet/return.

James 93SLC Mon Jul 30, 2012 3:54 pm

AtlasShrugged wrote: Bottom fitting is the ATF pressure outlet..top fitting is the inlet/return.

THANK YOU!

I was going to guess the opposite :oops:

Glad I asked 8)

AtlasShrugged Mon Jul 30, 2012 6:48 pm

That back end is where the ATF pump lives. The best way to think about it is the pump pulls from the sump (bottom) and pushes to the center (top) out to the torque converter.

James 93SLC Mon Jul 30, 2012 7:44 pm

AtlasShrugged wrote: That back end is where the ATF pump lives. The best way to think about it is the pump pulls from the sump (bottom) and pushes to the center (top) out to the torque converter.

Makes sense.

With your help I was able to finish up the install on my trans cooler setup.


72wagun Wed Aug 08, 2012 10:48 am

I ran across this thread while trying to determine how to hookup the thermostat on my Gowesty trans cooler kit. Since this was the only thread I could find with an answer I decided to call Gowesty to confirm this with them. They told me the opposite of the answer given here.

Gowesty said:

Top - Outlet
Bottom - Inlet

[Edit: See my later post below. I think the information above is incorrect now. I must have misunderstood what they were telling me. I'm sure they know what they are talking about.]

With two sources of conflicting information I decided to look for a third answer. I called http://www.germantransaxle.com in Bend Oregon. They rebuild these transaxles. I thought they should know how they work for sure. They confidently said that the top is the outlet, and the bottom is the inlet. Take it for what it's worth. I hope this helps others in the future.

PDXWesty Wed Aug 08, 2012 10:56 am

I'm not sure that it would matter which is which in this case when hooking up a heat exchanger as pictured here. It won't matter which is the inlet or outlet on the unit and the thermostat should work in either case on the supply or return line.

72wagun Wed Aug 08, 2012 11:06 am

PDXWesty wrote: I'm not sure that it would matter which is which in this case when hooking up a heat exchanger as pictured here. It won't matter which is the inlet or outlet on the unit and the thermostat should work in either case on the supply or return line.

I suspected that this was the case. The only thing that made me hesitate was that there are about 4 arrows on the thermostat housing indicating which way the flow is supposed to go. I bet you are right though. It probably doesn't matter.

AtlasShrugged Wed Aug 08, 2012 4:16 pm

The way to think about it..bottom is where the ATF comes from..Inlet..and exits to the center shaft and torque converter..outlet.

James 93SLC Wed Aug 08, 2012 8:04 pm

Well heck now I'm not sure.
There has to be a reason that there are flow arrows on the thermostat, so I'm inclined to believe that it is important to the operation. I wouldn't assume that it will still work correctly hooked up backwards.
With GoWesty and German Transaxle both saying the same thing, I'm thinking Atlas may have it backwards. However he has had one of these apart before, so he has some credibility. :?

I think I might disconnect my lines and crank the engine over to see which one the fluid comes out of to be 100% sure.

72wagun Thu Aug 09, 2012 8:17 am

AtlasShrugged wrote: The way to think about it..bottom is where the ATF comes from..Inlet..and exits to the center shaft and torque converter..outlet.

Atlas,

Thanks for your comments. I do really appreciate you sharing your experience. One of the reasons I checked with some other places was because I just like to have two opinions that agree with each other for additional confirmation. But, the other reason was because I wasn't sure I understood what you were saying in your earlier comments. I think there is room here for miscommunication here.

The way I read your last comment (quoted above), it seems that you agree with the other advise I got. I may have just misunderstood your earlier explanation. Is that correct?

In other words:

Bottom = Inlet (where fluid goes into the transmission)
Top = Outlet (where fluid comes out of transmission)

Thanks again for your help.

Moderator edit: The above info is incorrect. Skip down to this post.

James 93SLC wrote: Well heck now I'm not sure.
There has to be a reason that there are flow arrows on the thermostat, so I'm inclined to believe that it is important to the operation.

This was what made me want to check this out. I thought it was strange that Gowesty doesn't seem to mention this in the instructions (at least I didn't notice it). The thermostat maker didn't just put one arrow, but a bunch of them!

AtlasShrugged Thu Aug 09, 2012 9:01 am

Well, no not exactly. The ATF pump pulls from the bottom and sends the AFT through the top fitting.

When you look at the AFT pump and pick up channels from the filter in the transmission, it is the only way ATF can get to the torque converter/clutch packs and center shaft.

To test..remove the coil wire from the distributor and ground it.

Have a pan and your two loose hoses from the back of the transmission in the pan with the ATF cooler disconnected.

Have someone turn the engine over with the starter and see which hose the AFT comes out of. It should be the bottom fitting hose.

PDXWesty Thu Aug 09, 2012 9:16 am

James 93SLC wrote: Well heck now I'm not sure.
There has to be a reason that there are flow arrows on the thermostat, so I'm inclined to believe that it is important to the operation. I wouldn't assume that it will still work correctly hooked up backwards.


I agree. I was unaware of the type of thermostat they were using. It can sometimes be just a valve that modulates open and closed to regulate temperature. In that case, position in the system is less critical. If it's a t-stat similar to the engine type, flow direction is important. What isn't important is the in/out on the actual heat exchanger. Flow in either direction is the same.

MarkWard Thu Aug 09, 2012 1:26 pm

Post your findings.

James 93SLC Thu Aug 09, 2012 1:49 pm

rsxsr wrote: Post your findings.

It'll be a few days before I get a chance to investigate.

72wagun Fri Aug 10, 2012 9:49 am

AtlasShrugged wrote: Well, no not exactly. The ATF pump pulls from the bottom and sends the AFT through the top fitting.

When you look at the AFT pump and pick up channels from the filter in the transmission, it is the only way ATF can get to the torque converter/clutch packs and center shaft.

To test..remove the coil wire from the distributor and ground it.

Have a pan and your two loose hoses from the back of the transmission in the pan with the ATF cooler disconnected.

Have someone turn the engine over with the starter and see which hose the AFT comes out of. It should be the bottom fitting hose.

Okay. Thanks for explaining this.

rsxsr wrote: Post your findings.

I agree. I'd do it on my van, but I'm finishing up a Subaru conversion, and things still are not back together.

72wagun Sat Aug 25, 2012 7:27 pm

AtlasShrugged wrote: Bottom fitting is the ATF pressure outlet..top fitting is the inlet/return.

Hi Atlas,

Well I pulled the transmission hoses off and cranked the engine, and sure enough the hose from the bottom port shot out fluid. It looks like my earlier posts just muddied the water. Sorry about that. Thanks for your help.

James 93SLC Sat Aug 25, 2012 7:55 pm

72wagun wrote: AtlasShrugged wrote: Bottom fitting is the ATF pressure outlet..top fitting is the inlet/return.

Well I pulled the transmission hoses off and cranked the engine, and sure enough the hose from the bottom port shot out fluid.

Thanks for investigating this! I feel much better about my cooler setup. I still hadn't gotten a chance to check out mine. 8)

AtlasShrugged Sun Aug 26, 2012 11:25 am

72wagun wrote: AtlasShrugged wrote: Bottom fitting is the ATF pressure outlet..top fitting is the inlet/return.

Hi Atlas,

Well I pulled the transmission hoses off and cranked the engine, and sure enough the hose from the bottom port shot out fluid. It looks like my earlier posts just muddied the water. Sorry about that. Thanks for your help.

No problemo...when I took mine apart the fluid path is clear to see. Good luck and bon voyage.

Red Beard Sat Feb 09, 2013 6:58 pm

OK darnit, searched for this info and found this thread, and it is conflicting and not confidence inspiring. Can someone who actually knows first hand post:

From which of the two holes in the transmission does ATF exit the transmission to go into the transmission cooler?

This is necessary information for those using an inline thermostat and/or a unidirectional inline filter.

(I have hoses for my external cooler waiting to be hooked up.)

Thanks!!!!!



Powered by phpBB © 2001, 2005 phpBB Group