Adding a 5 Speed Trans Cooler? Anyone?

[C.Plavan]

Does anyone know of someone that has already done this? I tried searching WRX forums with no real luck. I can figure it out since I have done a few on other race cars, but I was hoping not having to recreate the wheel.

I know I will need a pump (no problem) and I have tons of oil coolers. I'm just seeing if I am going to have to tap fittings into the transmission, or if someone has used existing ports/bolts etc. (I really have not looked at the trans that closely). I'm just looking to recirculate cooler fluid to save the R&P. Just one port in and one port out, I'm not going to spray the gears.

[redfogo]

How cool are you looking to get? I have seen cars like the MR2 and 944 turbo use Loop/ non pump coolers just goes through an external loop/pipe outside the trans.

[Mechie3]

I've only seen WRX guys do trans coolers on auto transmissions. They're not cooling the gear oil though, just the trans fluid.

[Ironhydroxide]

I have thought quite a bit about trans coolers for the Wrx. I have a few ideas that may help you if you do decide to do it. Pm me.

[Sgt.Gator]

Phoenix Performance added coolers to my Diff and 5 Speed tranny on the LGT when they raced it in the Grand Am Cup.
So yes it's been done!
And since swapping in my 6 speed I've modified the system to work with it.

The quick explanation: You'll need -8AN lines. A pump that can take the heat. A cooler. A temp sender and gauge or run it to a data logger. You take the oil out of the factory drain with an -8AN fitting welded to a bored out drain plug. Then either to the pump or to the cooler. The pump manufacturers say to run it to the cooler first so that "cool" oil is running thru the pump so it doesn't burn up. Phoenix ran it to the pump first, then the cooler. The return line goes to a fitting on the passenger side of the tranny.

You'll need to fabricate/weld a fitting, but it's a piece of cake.

I'll post up pics today.

[C.Plavan]

I would prefer using a pump. I made a system for my 911 because I was blowing through R&P's (with 211 RWHP and 1900 pounds). The trans temp now mirrors the motor temp. I just had to tap a temp sender and one -10 AN fitting. I was able to utilize the drain fitting in the trans for the "out" portion of the pump.

http://forums.pelicanparts.com/uploads20/photo+21329959882.jpg

http://forums.pelicanparts.com/uploads20/photo+31329959897.jpg

I want to do something similar for my Legacy GT trans.

[RetroRacing]

Starting that next week, already have a gear drive pump (don't like the diaphragm ones anymore). installing a 180 degree switch to turn on/off the pump, looking for the best existing port to put the return line in, suction line in the drain hole. Will probably just remove an existing sensor, cut drill and tap the sensor body. add an inline filter before the pump to grab any fumunda before it goes through the pump and onto the gears. Will post pics.

[Sgt.Gator]

LGT 5 Speed Tranny:

The fittings. The one on the left is -8AN steel fitting welded into the plug on the return into the passenger side of tranny. The one on the right is a drilled out drain plug with an -8AN steel 90 welded in, which obviously goes in the drain hole:

https://lh3.googleusercontent.com/U3blhPq5xCcWDA4d5A9qV-TVLWzSXD-KEnrob5to6vc=w1049-h591-no

https://lh3.googleusercontent.com/uGGjpELp2MdzIRcG1zRCvv0fvT2oDHuTz1CizhqoD9U=w1049-h591-no

The Return location, passenger side:

https://lh3.googleusercontent.com/YlWuYOkI-Kbp5AYKegb6QqziOLItYkTPw9OZ9Tw1vrk=w1049-h591-no

https://lh3.googleusercontent.com/Nv5BExWSoIBW8IiHlGrZOpr3pI5ur8b6Rs0xAabaQqY=w1049-h591-no

One way flow check valve. There's also an inline oil filter not shown:

https://lh3.googleusercontent.com/ECLqd4MD5Gfh-pL8UHCPRY5SaJyRMrgM7Oi4VjQPyQQ=w1049-h787-no


And just to show Chad I can hang out with Porsche guys, the racer next to me at Pacific Raceways. He blew a front wheel apart a couple of seconds in front of me and spun in the middle of the track. I barely missed him, hitting him would have been a tragedy, I love his car. His family has owned it since it came from the new car dealer. MANY years of racing development in this one!

https://lh3.googleusercontent.com/4dnbcOPlswjNhOzZPuTZWKUPn8JCIUE-l-jxnKgpVt4=w1049-h591-no

https://lh3.googleusercontent.com/gFDVtMLCMM9nkIQ_aP9f4e29dM2eX5YI3zsj8whKOJY=w1049-h591-no

[C.Plavan]

Good stuff. Thanks for the info. I just ordered the fittings. I found a metric adapter for the top fitting (m22x1.5) I think that should work if the pitch is right. I have a second transmission, so I took the plugs out and will just weld those.

That Porsche is bad ***. Look at that Intercooler. WOW

[Mulry]

Is the return just coming back through the opening for the manual trans dipstick?

[C.Plavan]

Is the return just coming back through the opening for the manual trans dipstick?

The return line connects to where the speedo drive gear would go on a WRX. Gator and I have Legacy GT transmissions. They just have a threaded plug where the speedo drive gear would go.

I received all my fittings, I just need to fire up the welder. I also need to check clearance on the bottom transmission drain plug.

I have gps, so my speedo is on my Traqmate.

[Bob_n_Cincy]

I have gps, so my speedo is on my Traqmate.

Chad
When I took my car to TIC for tuning. Dom (the tuner) said that it needs the speedo hooked up to the Subaru ECU.
It uses that information for something. You also need the neutral switch as that disables AVCS when in neutral.

On your race car, I would put the oil back in the reverse switch hole and have it spray on fifth gear.
Bob

[C.Plavan]

Chad
When I took my car to TIC for tuning. Dom (the tuner) said that it needs the speedo hooked up to the Subaru ECU.
It uses that information for something. You also need the neutral switch as that disables AVCS when in neutral.

On your race car, I would put the oil back in the reverse switch hole and have it spray on fifth gear.
Bob

I have aftermarket 272 Cams. The tuner took care of it to where it is not a problem. He says on my ECU it only effected the idle parameters, so he input the variables (and totally fixed my Aluminum Flywheel stall! :) ) . He said we could disable it completely for what I'm doing.

The 5th gear hole is a great idea. That way we know the fluid is traveling through the length of the transmission. Anything to cool the R&P I'm game.

[Sgt.Gator]

Chad
When I took my car to TIC for tuning. Dom (the tuner) said that it needs the speedo hooked up to the Subaru ECU.
It uses that information for something. You also need the neutral switch as that disables AVCS when in neutral.

On your race car, I would put the oil back in the reverse switch hole and have it spray on fifth gear.
Bob

The back up light and neutral switch holes are much smaller. They might work but you'd have to neck down a bit. The neutral safety switch reports to the ECU so that's out.

On Legacys the speed sensor data comes from the ABS system.

[Ironhydroxide]

If you plumb just above the oil deflector on the center section then the upper gearset gets extra lubrication and cooling and the fluid would circulate through the trans more fully.

[Mulry]

If you plumb just above the oil deflector on the center section then the upper gearset gets extra lubrication and cooling and the fluid would circulate through the trans more fully.

Was just looking at the transmission sticky and then saw this. I'd like to keep the factory speedo gear so we have that data on our gauge cluster. Is there a hole already existing above the oil deflector on the trans case, or would we need to drill/tap in that location for an AN fitting? We're going to have the transmission apart next weekend to do the LSD install anyway, so I might as well get this on there at the same time. Thx.

[Ironhydroxide]

There is no port currently but you'll want to drill just in front of the center dividing plate and just barely to the passenger side. If you really want to get into it you could drill through the center plate just behind the oiling port and then plumb to that.

I'd love to see your solution for this when you're done.

[Mulry]

There is no port currently but you'll want to drill just in front of the center dividing plate and just barely to the passenger side. If you really want to get into it you could drill through the center plate just behind the oiling port and then plumb to that.

I'd love to see your solution for this when you're done.

I'll document the process with photos, probably in a new thread since I can't find any LSD DIY threads that have any photos. There's a thread on nabisco that has a brief but probably-good-enough written description to get us through the process. Hopefully.

On a related topic, is there a preferred/accepted transmission oil blend for this application? I saw that Chad is using Swepco 201 because that's what the Porsche guys swear by, and then there's some others recommending a mix of Redline light shockproof and Motul (I assume 75/90 with LSD addidtives)? That topic probably deserves its own thread too, but I'm not convinced that I'm doing a very good job searching for it; when I type "LSD" into the search tool for this forum, it says "no results," which I know isn't true. Cheers.

[Hindsight]

.... since I can't find any LSD DIY threads that have any photos.

http://thefactoryfiveforum.com/showthread.php?16706

;)

[Mulry]

http://thefactoryfiveforum.com/showthread.php?16706

;)

TYVM! I swear that I searched that exact term and didn't find anything. My search skills used to be so good...

[STiPWRD]

TYVM! I swear that I searched that exact term and didn't find anything. My search skills used to be so good...
The search feature on this forum is lacking so it can take a while to find stuff.

As far as trans fluid, for years I've been running 3 quarts of shockproof light weight and 0.75 quarts of motul synthetic 75W90. This mix is recommended by Andrewtech.

[Ironhydroxide]

Shockproof clogs synchros. Just FYI. I wouldn't run it in any transmission.

[Mulry]

Shockproof clogs synchros. Just FYI. I wouldn't run it in any transmission.

So what do you run?

[STiPWRD]

Shockproof clogs synchros. Just FYI. I wouldn't run it in any transmission.
I ran shockproof for at least 7 years and never had issues with my syncros. Have you seen that with stock ones? I have ppg syncros and gears.

[Ironhydroxide]

I have disassembled many transmissions that have had shockproof in them. Every one has it's groves packed with the "beads" that are supposed to help the gears from wear. Many of these transmissions have their oiling ports plugged and the needle bearings showing wear and overheating more than others.

[Mulry]

I have disassembled many transmissions that have had shockproof in them. Every one has it's groves packed with the "beads" that are supposed to help the gears from wear. Many of these transmissions have their oiling ports plugged and the needle bearings showing wear and overheating more than others.

This is very concerning for a thread that's focused on adding an oil pump to the transmission coolant system. Seems like based on your observations, a cooler and pump could clog up with shockproof, which pretty much obviates the intended function of the system.

So what do you think would be a suitable alternative to run? Just straight Motul 300? Redline 75w90? With limited slip friction modifier?

[Ironhydroxide]

I personally run either amsoil severe gear 75w90 and Lucas synthetic oil stabilizer in my transmissions. (Or if I'm feeling"cheap" Lucas 80w-90 and synthetic oil stabilizer (3:1 ratio for both)

I find the stabilizer takes almost any gear oil and makes it cling to the gears and shafts better. Good for both dry starts where the trans has had time to sit unmoving, dripping the upper bearings dry, and for preventing gear root pitting.

[Mulry]

As promised, documentation of locating a return oil line for the transmission oil cooler.

We had the transmission apart anyway to do the installation of the limited slip transmission (thanks again to Hindsight's excellent LSD instructions thread at http://thefactoryfiveforum.com/showthread.php?16706). Owing to the suggestion of Ironhydroxide, I drilled and tapped the transmission case to accept a fitting above the fifth gear in the transmission. Here's how it goes.

Tools you'll need:
Hand drill
Drill bits (up to whatever you need for your tap size; for me, it was up to 7/16")
Center punch
Tape measure
Marker
Tap & tap handle
Cutting oil
Shop Towels

I started off by fixing the passenger half of the transmission case in my vise with some soft vice faces so as not to foul the case where it will meet the other half of the case when re-assembled. I wanted to retain the stock transmission gear and I wanted to locate the fitting to make sure that the threads would have sufficient support in all directions, nothing sucks like stripping a fitting and I didn't want to have to weld-fix an aluminum transmission case. The passenger side of the transmission case has a nice open area above the fifth gear that is about 1.6" wide from the parting line at the center of the case to where it starts to curve around on the outside. Here's the area I'm talking about:

47457

The measurement isn't exact, but it's close enough for what we're doing here:

47456

I like that nice, non-webbed area there. Using the Price Is Right Theorum, I wanted to use the largest size fitting I could find without going over into that hole on the left (that captures a dowel from the driver's side of the case) or into the webbed area to the right. I had a 1/4NPT tap in my tap and die kit, which requires a 7/16" drill bit (or 0.4375"). 1/4NPT to -8AN adapters are pretty easy to find and using -8AN fittings and hose should provide sufficient oil flow for this application (plus I have a bunch of -8 hose & fittings on my shelf), so I went with that size, although I think there's probably enough meat on that case to go up to a 3/8NPT fitting if you wanted to do that (YMMV, measure twice cut once, standard disclosures, etc.). As you can see, there is well more than 0.438" on either side at that location, so I marked it for center.

47458

0.75" is a lot easier to mark than 0.80 inches using a tape measure, and since the location of this hole doesn't need to be that precisely located (within 5-thousandths, at least), I took a little liberty. So I located the center of the hole and punched it for drilling at 3/4" from the edge of the parting line of the case and 2-15/16" from the rear edge of the transmission case:

47459

After drilling the hole, there was still plenty of room on either side for the tapping process to begin. I didn't take any photos of the drilling, but if you are going to use the same size fitting as I used, there is plenty of room there to work in without worry about hitting the hole or webbing to either side (as you can kind of tell from the photo below).


I suggest putting shop towel in the case and wetting it down with cutting oil to catch most of the swarf from the drilling and tapping process to make it easier to clean the case after the procedure. Start with a small drill bit and work your way up. My last drill bit was a 7/16" bit, followed by the 1/4NPT tap:

47460

And thus you now have a threaded location for a transmission oil cooler return line. I'll edit this with a photo of the fitting installed when I receive it.

All in all, this was a really easy process and probably took about an hour , including taking the photos. I'd guess that it would take about 30 minutes if you had the tools all assembled before you start the job. Cheers.

[Ironhydroxide]

Ah, that's not where I was meaning. I mean in the center section above the oiling return for the upper shaft. I'll update with a picture after uploading

[Mulry]

Ah, that's not where I was meaning. I mean in the center section above the oiling return for the upper shaft. I'll update with a picture after uploading

Lol. I'd love to see the photo but I don't see changing it at this point :)

[Ironhydroxide]

http://i757.photobucket.com/albums/xx213/ironhydroxide2/Mobile%20Uploads/2015-11/IMG_20151109_191330_zpsvsefdiqh.jpg (http://s757.photobucket.com/user/ironhydroxide2/media/Mobile%20Uploads/2015-11/IMG_20151109_191330_zpsvsefdiqh.jpg.html)

The plastic portion is what feeds the 3-4-5 gear bearings, if you feed into this plastic portion you'll guarantee the oil gets to the most worked portions of the transmission, especially because any overflow goes to the bottom of the case and through the bearings/feed holes back to the oil pickup. Just above the step is where I'd suggest welding in a return bung to be sure of enough material to thread a fitting in.
http://i757.photobucket.com/albums/xx213/ironhydroxide2/Mobile%20Uploads/2015-11/IMG_20151109_191338_zpsgkayfyd2.jpg (http://s757.photobucket.com/user/ironhydroxide2/media/Mobile%20Uploads/2015-11/IMG_20151109_191338_zpsgkayfyd2.jpg.html)

[Mulry]

That location makes sense. Since I've already got this hole tapped I think I'll go with this for now and monitor the trans oil temps once racing, if they become problematic then we can always pull it and add that bung.