Differential Temp Probe Conundrum

Joined
Feb 9, 2021
Messages
71
Alright I've got an interesting one for ya'll

I want to keep an eye on my differential fluid Temps at the track. I've got a guage all wired up and I just need to install the probe. I have this fancy diff cover shown in the pics. As you cna see it's TIGHT in there. Cover a not come off without the pumpkin coming out.

Sooo... Initially I planned to use the 1/8npt probe into the adapter and put it in where the drain plug is now. Then I remembered that drain plug is magnetic. It does pick up quite a bit of metal between oil changes (changed once a year).

Options:
1) put the adpater/probe into the drain hole and just send it
2). Put adapter into drain hole and magnet into fill hole. Will this still do a decent job of picking up the metal "dust"?
3). Try to drill and tap the cover where the little probe inlet is on the side while the pumpkin is on the car. I only have 2.2" of space but can figure that out. Just worry about an aluminum burr falling off into the diff while it is running.
4). Spend a whole day taking apart the exhaust, the suspensions, all the axles and driveshaft to get that pumpkin down in my tiny Chicago garage, take off the cover, tap the hole, and put it all back in the next day after the rtv cures. This clearly is the suckiest option for just a stupid temp probe.
5) say "screw it" and put the probe into the transmission drain plug as I should keep an eye on that as well.

Any tips or tricks to tapping that hole on the side with only 2" or so space let me know. I made a bit that will fit and my tap will fit. I assume if I do it with the diff full of fluid most chips from drilling will come out as the fluid drips out
 

Attachments

  • Screenshot_20230112-080744.jpg
    Screenshot_20230112-080744.jpg
    55 KB · Views: 13
  • Screenshot_20230112-072725.jpg
    Screenshot_20230112-072725.jpg
    49.4 KB · Views: 14
  • Screenshot_20230112-081304.jpg
    Screenshot_20230112-081304.jpg
    57.8 KB · Views: 12
  • Screenshot_20230112-081027.jpg
    Screenshot_20230112-081027.jpg
    51.1 KB · Views: 12
  • Screenshot_20230112-080953.jpg
    Screenshot_20230112-080953.jpg
    40.6 KB · Views: 12
4) is the best way, but given the amount of work and your Chicago garage is probably cold now, 2) works. There is so much fluid being flung around that the magnet will certainly catch some if not most of what dust it would catch in the lower position.

One concern is the durability of the temp probe vs. a drain plug if you hit something, however the cooling fins appear to shield the drain plug so that may not be a problem on the diff, but certainly something I would think about on the transmission.

What car?
 
4) is the best way, but given the amount of work and your Chicago garage is probably cold now, 2) works. There is so much fluid being flung around that the magnet will certainly catch some if not most of what dust it would catch in the lower position.

One concern is the durability of the temp probe vs. a drain plug if you hit something, however the cooling fins appear to shield the drain plug so that may not be a problem on the diff, but certainly something I would think about on the transmission.

What car?
It's an 07 350Z I mostly take the track but it's still street legal.

I was thinking #2 would work just fine. Plus I change the fluid before every season. I could always run it for a year and check the fill plug to see what it has picked up. I also assume it gets sloshed side to side quite a bit on track since I'm pulling over 1.4G laterally.

The other concern I had with it being in their little "temp probe position" is it seems like it is too high of a position. I've seen the videos with the clear diff covers and that fluid line drops dramatically as soon as it starts running. I'm sure that just put that probe position wherever they could and didn't do any sort of running level analysis
 
I vote #2.
Any misgivings about this being mounted horizontally instead of vertically? In terms of strength that is. It is OEM so I assume that magnet is stuck in there pretty good
 

Attachments

  • Screenshot_20230112-100253.jpg
    Screenshot_20230112-100253.jpg
    44.1 KB · Views: 2
You are already changing fluid every year how much "dust" could be floating around? I'd say the magnet is really not necessary, but install it in the fill hole if it you want. When you say quite a bit of metal what do you mean, dust or whiskers? I've seen magnets come out of neglected diffs, like not changed for many years, and there was only a paste type build up.
Just curious, what to you think the max temp of the diff fluid will be?
 
Last edited:
You are already changing fluid every year how much "dust" could be floating around? I'd say the magnet is really not necessary, but install it in the fill hole if it you want. When you say quite a bit of metal what do you mean, dust or whiskers? I've seen magnets come out of neglected diffs, like not changed for many years, and there was only a paste type build up.
Just curious, what to you think the max temp of the diff fluid will be?
It just comes out as a gummed up "glue" now. I slapped an OS Giken 100% lock LSD in there so intilaly then ring and pinion had to mate up again. Changed it after 500 miles and then again after 3000. It had quite a bit on there after those two. Last year there wasn't too much on there.

But there are 28 clutch plates inside of my differential so I'd like to keep the oil free of any oil. I'm sure race teams would laugh at me and Change it after every race.

The diff requires two quarts of unicorn tears. At a whopping $65 a quart... I only change it once a year
 
Back
Top