Originally Posted by cactus (Post 3484934)

I was going to use the fill hole with an M18 x 1.5 oil galley plug that has 1/8 NPT in it.

Originally Posted by Ohio Enthusiast (Post 3485076)

Is the fill hole submerged in oil? I thought you needed to fill it until it just trickles out of the fill hole, hence there wouldn't be enough oil for the sensor to read. The drain hole sounds more appropriate for this, no?

Originally Posted by Matt93SE (Post 3519163)

So digging this one back up since I haven't logged onto this forum in months and came back on here to ask about trans temps...

So I completed the task by buying some brass adapters from the metric threads to a 1/8" NPT. Then I stuck a temp sensor in the plus and screwed them into the fill plug on both trans and diff. This keeps the magnets on the drain plugs. I would prefer to have the temp from the bottom of the 'sump', but don't want to risk not having a magnet for debris.

Sooooo.. now for the fun.
After a 35 min race on a short track (Hallett) in 65F weather.. Transmission and diff temps slowly rose through the race and eventually levelled off after about 25 min on track.

Temps topped out at 298F for the trans and differential was about 265F.
this was with NEW fluid- Redline MT90 + superlight Shockproof in the trans
Redline 75w90 gear oil in the diff.

What's interesting is that the engine temps came up and stabilized by lap 3 while it took another 20 laps for the trans and diff to stop going up.

Next question is whether I bother with installing trans and diff coolers or not, or just deal with 'frequent' fluid changes. I get about 5-6 race weekends a year, with ~2-3hrs of seat time per weekend. Thus the fluid sees about 15 hours of use and then I change it. I'm thinking based on those change intervals that I might as well not bother with a cooler. That said, the ambient temp at the track was in the low to mid 60s and summer TX weather has ambient temps in the 90s for many of my races.. dilemmas dilemmas dilemmas...

Originally Posted by rice_classic (Post 3519174)

Nice data. We wrap our overpipe/frontpipe which greatly helped our trans fluid and added little aluminum heat shields where the exhaust passes by the axle/diff along with greddy cover and that fluid lasts much longer now. Trans fluid OCI went from every weekend to every 3-4 weekends and diff every 5ish and now it can do longer than 45 minute races whereas with no shielding or diff cover I was burning my diff fluid within 45 minutes and spitting it out the breather.

I would be curious to see your temps if you added wrap/shielding. Your trans temp suggests that you should prioritize this.

Originally Posted by Muskoka800 (Post 3519245)

Have you considered moving the sensor plug down to the drain position for a test? Perhaps the readings would rise faster/higher if the sensor was submerged rather than being marginally above the oil and only splashed. If I recall the plugs are the same size, at least on the diff.

Originally Posted by Matt93SE (Post 3521426)

Thanks for the insight. That was kinda the point of the testing-- I had some contingency money to spend at a local shop before end of 2021 and he had the AIM sensors on the shelf, so "hey let's do some science" heh. always better to measure and bring some info to the table vs. just asking questions. now I'm armed with a little data from a single race and I can make adjustments and see how it goes.

Due to life schedule, I only get to do about 3-4 races a year, so fluid typically ages out vs. wears out. (in short, I change it once a year whether it needs it or not!)

But I do plan to add some heat barriers/shielding, just haven't gotten there yet. I have a large sheet of the DEI 'floor and tunnel shield' and also some header wrap laying around.


My more immediately pressing issue is to get the brake cooling back under control. I had a wreck last year that tore all the brake ducts up. I ran the last race without them due to lack of time, but the additional heat used 90% of of pads in a single weekend whereas I used to get 3-4 weekends out of a set.:thumbdown:
So Verus Eng/ Velox brake ducts and steering rack limiters are sitting on the shop floor with some new 3" hose. If I get time, I'll put some sort of heat shield on the exhaust around the trans and maybe diff.



I don't think it'll make much difference in the temps. since the fluid is sitting *juust* beneath the temp sensor in a static setting, that stuff is getting circulated and thrown everywhere inside the case when I'm moving- splashing from the gears and sloshing from the whole sump as I turn and brake. the sensor is thus basically dunked in gear oil every other turn or brake zone so I'm confident I'm getting "good enough" data. not real concerned about the exact +/- 1deg data, but the +/- 20deg that tells me whether the fluid is going to last a while without a cooler or if I need to add some cooling.

Additionally, the metric to NPT adapter thingies are sealed with an o-ring against the case. I don't feel real comfortable putting that at the bottom of the trans and risking losing ALL my fluid if that seal fails, plus losing my tattletale shrapnel magnet. :)

Originally Posted by rice_classic (Post 3519174)

Nice data. We wrap our overpipe/frontpipe which greatly helped our trans fluid and added little aluminum heat shields where the exhaust passes by the axle/diff along with greddy cover and that fluid lasts much longer now. Trans fluid OCI went from every weekend to every 3-4 weekends and diff every 5ish and now it can do longer than 45 minute races whereas with no shielding or diff cover I was burning my diff fluid within 45 minutes and spitting it out the breather.

I would be curious to see your temps if you added wrap/shielding. Your trans temp suggests that you should prioritize this.

Originally Posted by Muskoka800 (Post 3519245)

Have you considered moving the sensor plug down to the drain position for a test? Perhaps the readings would rise faster/higher if the sensor was submerged rather than being marginally above the oil and only splashed. If I recall the plugs are the same size, at least on the diff.

Originally Posted by DrinkenBRZ (Post 3521442)

Rice, you’re still running the Pennzoil Synchromesh too aren’t you? Impressive conventional at those temps and counter intuitive.