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Charlie Clark has one on his E Production car. He is using a small cooler with an electric fan mounted behind the LR tire. He is using -6 lines and a Tilton pump. No thermostat, he just turns it on.
Probably something like this: https://www.ebay.com/itm/27252575064...3ABFBMurOPj7pg
He also runs Amsoil 75/140 racing gear lube and I do too. I put bungs in the back of my housing and have the pump, hoses and fittings but haven't gotten around to installing anything.
Im wondering if with bigger (and shorter) lines, maybe -10, it would work without a pump. I imagine the crown wheel itself would be forcing quite a bit of oil pressure against the back of the pumkin at speed.
Sorry it took so long, but comment back from my friend is that he doesn't see much, if any advantage to the passive cooling scheme. Seems like the consensus is that a pump and cooler (preferably with a fan too) are the way to go, if you continue to have problems. Like I said, I have not have any problems with my 4.3 with clutch LSD over many-many hours of racing. I have no idea what my fluid temp is. I do change fluid after every enduro weekend and every other sprint weekend. And again, I only have about 150 hp at the wheels. For speed reference, I think our fastest lap time at PIR a couple of years ago was 1:38, so notably slower than you guys. We had some issues that I am sure slowed our adaptation to the track, but I suspect we couldn't drive much faster than maybe 1:36.
Sorry it took so long, but comment back from my friend is that he doesn't see much, if any advantage to the passive cooling scheme. Seems like the consensus is that a pump and cooler (preferably with a fan too) are the way to go, if you continue to have problems. Like I said, I have not have any problems with my 4.3 with clutch LSD over many-many hours of racing. I have no idea what my fluid temp is. I do change fluid after every enduro weekend and every other sprint weekend. And again, I only have about 150 hp at the wheels. For speed reference, I think our fastest lap time at PIR a couple of years ago was 1:38, so notably slower than you guys. We had some issues that I am sure slowed our adaptation to the track, but I suspect we couldn't drive much faster than maybe 1:36.
That pretty much confirms my thoughts. Thank you for asking him. I'm hoping we have our cooler install finished this Sunday and I'll post some pictures. All that's left now it attaching lines to the housing. Finding the right fittings and such has been a challenge. Using the fill plug hole as the return which as I measured is 20mm x1.5. I'm on my third order of what is supposed to be that size. The plan is to drill a hole below that for the feed and weld on a 1/2"npt bung to screw the fitting into. The first run I ordered to that description was almost twice the diameter I expected. Sure would be nice if this kind of stuff was available at a store I could look at and compare to get the right thing. Sucks that everything is available only mail order these days.
Charlie Clark has one on his E Production car. He is using a small cooler with an electric fan mounted behind the LR tire. He is using -6 lines and a Tilton pump. No thermostat, he just turns it on.
Probably something like this: https://www.ebay.com/itm/27252575064...3ABFBMurOPj7pg
He also runs Amsoil 75/140 racing gear lube and I do too. I put bungs in the back of my housing and have the pump, hoses and fittings but haven't gotten around to installing anything.
Scott, can you by chance post pictures of how you installed the bungs?
Last edited by Conekiller13; 07-13-22 at 10:34 AM.
Reason: Spelling
Scott, can you by chance post pictures of how you installed the bungs?
The return bung is about 2" above the OE fill plug and the supply bung is below the OE fill plug.
I have the same pump and a slightly smaller cooler. My plan was to put the pump on the left side in front of the rear axle and place the cooler in the left rear well in the area where the factory gas tank filler was. I was going to source air from the passenger side window with a dual port head light duct. One hose to the oil cooler and the other to my helmet blower.
Last edited by mustanghammer; 07-26-22 at 12:23 PM.
The return bung is about 2" above the OE fill plug and the supply bung is below the OE fill plug.
I have the same pump and a slightly smaller cooler. My plan was to put the pump on the left side in front of the rear axle and place the cooler in the left rear well in the area where the factory gas tank filler was. I was going to source air from the passenger side window with a dual port head light duct. One hose to the oil cooler and the other to my helmet blower.
Thank you. So, as you can see, we used the fill plug as the return. Do you think it needs to be placed higher? That sounds like good placement for your cooler and the pump should work in front since you have the three link and panhard.
Last edited by Conekiller13; 07-26-22 at 12:38 PM.
Thank you. So, as you can see, we used the fill plug as the return. Do you think it needs to be placed higher? That sounds like good placement for your cooler and the pump should work in front since you have the three link and panhard.
I would say that as long as the rear end is always full it should be fine. Too much rear end lube eats power
Am I the only one that laughed at that last phrase? You're right, just leave it.
Cool pump set up BTW. Some sort of air scope at the old gas fill door?
Thank you. Yea, after installing I realized there is no real air flow where the cooler itself is mounted. I looked at doing some kind of scoop under the cell but I thought cooler air from the side would be more effective and I had the brake duct tube lying around. The actual scoop is a marine part though...
We'll see how well it works this weekend. Race at Oregon Raceway Park. It's supposed to be 105°F during practice on Friday. They moved the race starts to 7am Saturday and Sunday to get in cooler temps. Supposed to be 106°F on Saturday and 103°F on Sunday.
Am I the only one that laughed at that last phrase? You're right, just leave it.
Cool pump set up BTW. Some sort of air scope at the old gas fill door?
I know a guy that had a full rear end in the middle of a race, and it wasn't the one on the car. He said it was "unpleasant" but he did win the race. He had a spare suit for Sunday.
So, next update...we had a race two weeks ago at Oregon Raceway Park. Friday practice was around 105°F in the early afternoon. The diff cooler was working well once we realized the thermostatic switch wasn't getting the fluid temp to it. We wired the pump to a switch and diff temp went from 275° to 215°. We start the race Saturday which they moved the start time from 10:00am to 7am due to heat forecast and 1 hour stints instead of two hour stints. It was about 80°f ambient at race start. I started the race and ran the hour with no real issues. Rear diff temps around 220°, engine coolant at 200° and engine oil around 230° towards the end of my stint. We were starting to plan pace based on engine oil temps. At the one hour mark we make the driver change. Second driver goes out and within four laps he's hearing gear whine from the rear and checks diff temp. Temp had shot from 220° to 375°. He pulled in. We verified cooler pump was still working. With everything assembled pinion lash felt excessive. We were done for the weekend after 24 race laps. Post race partial tear down revealed pinion backlash wasn't really that excessive but it was more than when initially assembled. Wear pattern on drive side of gears looks perfect but coast side has excessive wear. Drivetrain shop hasn't disassembled third member yet so not quite sure what the cause is. Hopefully the new ring and pinion aren't ruined. The only "mistake" I can think of we made was there was no real "break in" time giving to the new ring and pinion. I found out after the P.I.R. race you are supposed to bring the diff up to temp slowly than let it completely cool before pushing.
So the moral of the story is the diff cooler works but we have issues...
P.S.
I'm hoping maybe a cheap NAPA pinion bearing is/was the culprit....
Last edited by Conekiller13; 08-12-22 at 10:18 AM.
Reason: post script
Just got word from my Drivetrain guys, looks like the crush sleeve collapsed. I think this is what took out the last one also and not initial set up. Maybe something with the super short gears (4.87) makes too much pressure on it? Anyway, the next plan is crush sleeve eliminators. Weir Performance - Solid Pinion Spacer Kits
Picking up another complete third member today with 4.44 gears and maybe that will also help.
Just got word from my Drivetrain guys, looks like the crush sleeve collapsed. I think this is what took out the last one also and not initial set up. Maybe something with the super short gears (4.87) makes too much pressure on it? Anyway, the next plan is crush sleeve eliminators. Weir Performance - Solid Pinion Spacer Kits
Picking up another complete third member today with 4.44 gears and maybe that will also help.
The guy that sets up my diff's - David Long @ www.SantaFeGarage.com makes a solid shim every time. Some advantages beyond the fact that they cannot collapse is that I can swap pinion flanges without worrying about messing up a crush sleeve. He does this on all the rear ends he builds - 9" Ford, 8.8 Ford, etc.
I asked David Long at Sante Fe Garage about the solid sleeves that he makes. I figured it would be a pretty easy process. It isn't
I asked him if the solid sleeve is just a copy of the compressed crush sleeve. Below is his answer. I asked for his permission before I shared this information. I would add the David has prepared all of the third members for my RX7 and he also built the 8.8 rear end I had in my old autox mustang.
Scott:
Yes, the solid sleeves are a copy of the original crush sleeve in that they taper from the big end to the small end. They are thicker as you do not want them to crush. I usually make the wall 3/16" thick (0.1875"). I start with the original crush sleeve and machine a new one from 4130 (chrome moly) or 12L14 (stress proof). I make it about 0.010" longer than the crushed sleeve removed. Then, I set up the pinion preload using "slip fit" bearings. Slip fit bearings are new tapered roller bearings that have had their centers honed to allow a slip fit as opposed to a press fit. It is back to the lathe or surface grinder, depending on the height of the sleeve to remove a few thousands at a time until the proper preload is achieved, about 15 to 20 in/lbs (assuming new bearings are to be installed). Once the preload is set, its off with the slip fit bearings and on with the new bearings. Then, a final check of the pinion preload. If, OK, install the seal. With the solid spacer, the pinion can be removed and reinstalled; a little loctite and 150 to 200 ft/lbs (depending on the pinion size, 150 for Mazdas). This works even if you change the bearings as the tolerances from the quality bearing manufacturers vary less than 1/2 a thousandth (0.0005").
More info...
The pinion depth is also set during this process because the pinion depth shims are located between the pinion gear and the large pinion (inner) bearing. Note: the solid pinion spacer is matched to the housing. That is, even if you change the ring and pinion gears, the spacer will be the correct length. If you change the ring and pinion gears, you will probably have to change the shim(s) between the pinion gear and the inner bearing, but the distance between the bearings will be the same for a given housing.
Thank you for asking. David Long, ASE Master Technician
407 West Lexington Ave
Independence, Missouri 64050
816-977-1020 SantaFeGarage.com
So, latest update. The rear differential survived last weekend. Almost 1100 race miles completed. We took 3rd in class on Saturday and 4th on Sunday and got the Haag Motorsports award for most laps turned in a Mazda powered Mazda. Anyway, the 4:44 gear set stayed cooler but definitely had a negative effect on lap time. We lost about 4 sec a lap compared to earlier this year at the same track. Ambient temp was in the low 90's so a bit cooler outside than the last two race weekends. Rear diff temps were mostly in the 240 to 260 degree area with a few spikes up to 275 degrees for short term. Next step is to build an actual air intake Infront of the cooler to force the air through it instead of just Infront of it. The biggest problem of the weekend was the transmission blowing oil past the tail shaft seal. It was coming out fast enough to spray the exhaust and blow smoke on left hand turns but not leaving any residue on track. By the end of Saturday's race there was only about 1/2 a quart of fluid left in the transmission. We filled and again on Sunday blowing smoke for the first couple hours. By the last two hour stint the 4th gear synchros had given up. My driver ran almost his whole stint going 3rd to 5th or getting a perfect rev match to get 4th. So now we have that issue to figure out. We've always lost fluid from the shifter tower (enough to puddle on the passenger side floor) with this transmission but never more than just a mild seep from the tailshaft seal.
On my mustang autox car, I modified the speedometer driven gear ferule and added a 3/8 hose barb to it. I attached a hose to the barb and ran it to a breather tank in the engine compartment.
On my mustang autox car, I modified the speedometer driven gear ferule and added a 3/8 hose barb to it. I attached a hose to the barb and ran it to a breather tank in the engine compartment.
Right now the transmission just has stock/factory venting whatever that may be. We were thinking maybe we needed to add a vent just like you described. We were looking at using the reverse sensor hole as its on top and the speedo hole is in the bottom. Sounds like we were thinking correctly...
07-05-22, 07:41 PM
