Manual Transmission Oil Cooler

I have a oil cooler on my 1988 manual transmission. I assume this is stock?

Doubtful

Assuming you have a ZF, no, it never came with a factory oil cooler. (Pretty sure the cast iron 4-speed didn't come with one either.) If I recall correctly, an oil cooler didn't come stock in manual transmission-equipped trucks until '99 with the ZF-6.

Maybe clarify for us.

1) Your engine came with a oil cooler bolted to the drivers side of the block. Then yes that is stock For all IDI’s.
or
2) You have something that helps cool your tranny fluid on your manual transmission. If so what does it look like or do to cool?
or
3) You perhaps have hook ups for a tranny cooler in the radiator or perhaps a tranny cooler in front of the radiator. But perhaps someone converted your truck from auto to a stick.

Let us know.

Merry Christmas!

I read this as having a transmission cooler in the radiator. If that's the case, a lot of aftermarket radiators come with a transmission cooler and it's connections already inside. That way one radiator can be used for both automatic or standard transmissions. At least the radiators used to come that way. I'm not sure about today.

It is a dedicated manual transmission cooler. The installation looks factory and if it's after market, it's very well done. Port in each PTO cover, rubber lines to what could be an electric pump on the top side of the cross member, driver side. Steel lines from the cross member/frame rail connection to a small dedicated cooler in front of the radiator on the passenger side, looks like they could be lines for an automatic, not just straight sections, they look like factory lines, I'll post pictures later. Truck was used for towing horse trailers. It also has a Mitchell splitter with a temperature probe (not connected).

That's unusual for sure. I doubt that it's factory though.

Definitely interested in pictures, please share them. Sounds like it could be a good add to any truck hauling often.

I bet mitchell furnished it...

You answered my initial question of - How does the oil flow through the cooler? Seems like a good setup if you tow regularly. If they went though all the trouble to plumb in a manual trans cooler, I sure hope the plumbed in a gauge. Only in the summer months do I concern myself with trans temps. Rarely does my gauge come off of the peg at 100F. In the summer it hangs around 180F on a long pull. This is an apples to oranges comparison, I'm giving numbers from a Fuller/Eaton 13 spd with a 4 gallon capacity pulling 112,000 lbs gross. My ZFs don't have gauges and the most I ever gross is 26K, and they are short trips.

Trikebent said:

It is a dedicated manual transmission cooler. The installation looks factory and if it's after market, it's very well done. Port in each PTO cover, rubber lines to what could be an electric pump on the top side of the cross member, driver side. Steel lines from the cross member/frame rail connection to a small dedicated cooler in front of the radiator on the passenger side, looks like they could be lines for an automatic, not just straight sections, they look like factory lines, I'll post pictures later. Truck was used for towing horse trailers. It also has a Mitchell splitter with a temperature probe (not connected).

Click to expand...

That is a first I have heard of a manual tranny cooler On a IDI.

As mentioned above please attach some pics, this is a rare beast and will be cool to see how it is plumed and works.

My guess is you are correct, they added a external pump to circulate the ATF/gear oil through the lines to the tranny cooler behind the grill. I believe because manual transmissions don’t usually have a pump, tranny coolers are not common. But adding a external pump would solve the issue Of how to circurate the atf/gear oil to a cooler.

The only picture I'm willing to get today ! I'll post pictures in a few days.

definitely interested in more pics, I have seen a couple setups similar to what you are describing on 3rd gen dodge (03-07) but never on a idi.
I did run for a long time fabcraft pto cooler/heat sinks that add 1 qt per side of additional fluid. i ran those and a trans temp gauge until i swapped trans and was tired of them always leaking.

Ok, snow has melted... It is an add on. Fittings added to each access/side/PTO cover. 1/8" npt to 5/16" hose barb fitting in each cover. One, passenger side, about 1" up from bottom edge of cover, the other, driver side, is about 3" up from the bottom edge. Hose on drivers side is connected inlet side of a Walbro 12v-801 fuel pump bolted to the cross member. Pump out connects to 5/16" aluminum line that runs along crossmember to pass side frame rail, then runs forward to the radiator area. Hoses connect to the cooler mounted in front of the A/C condenser. Hose connects to aluminium line back to passenger side of transmission. Hose connects aluminium line to hose Barb fitting on pass side transmission cover. Pump is controlled by a toggle switch on the dash. No temperature gauge was installed. I'm currently installing a gauge. Bench test showed the Walbro to be intermittent when powered on. Given the age and non availability of the Walbro. I will replace the Walbro with a Holley "Red" pump. I will also change the flow to out on the lower passenger side and in on the higher side port.

Very cool, got more pics for us? where does the pump mount? To be honest, NPT fittings screwed into the PTO Covers sounds like a hack job to me but maybe thats the best way to do it. Couldnt one line be plumbed from the drain port and the other plumbed to the fill port? Maybe the drain port fitting would be too exposed to road debris and damage but a skid plate could be made to shield it.