borgerding

Does anyone know where the "pressure port(s)" are located on a model 10 - 375 RHM "Slim Jim" transmission?
I want to install tranny fluid pressure/temp sensors to help diagnose a slippage issue.
The car is a completely stock 62 Starfire 394 V8 with the typical Slim Jim - 375 RHM model 10 tranny.

(Fluid level is correct and repeatedly checked. Carb/TV linkage have been adjusted and triple checked per service manual.)
Primarily notice a slip in all ranges but typically only when engine/tranny are hot?
Recently installed auxiliary tranny fluid cooler with separate fan and 2 auxiliary radiator cooling fans.
These additions seem to help a bit, but they don't fully alleviate the issue, especially after driving on highway for 10 minutes or so. (Ambient temp outside being around 50 - 60 deg F.)
Engine temp gauge after driving in these conditions falls between 160 -180 deg. F.
Thank you all in advance!

Olds64

I was looking for a picture of a Slim Jim online to find the pressure port, but there aren't any clear pictures. I owned a 64 98 years ago with a Slim Jim. Even though I rebuilt it I could never get it to shift correctly. If I owned another classic Oldsmobile with a Slim Jim I would just replace it with a different transmission (TH400 or 700R4).

As I recall, the pressure port was just in the side of the transmission case like any other automatic. Good luck!

Charlie Jones

Everyone dismisses the" slim Jim ' transmission .
Because , " the guys that know how to work on them are all dead " .

But , how did the guys that worked on them 50 some years ago learn how to fix them ?
The answer is the Oldsmobile Chassis Shop Manual .
That book will tell you everything you want to know about servicing , diagnosis and repair of the " slim Jim " .
You will need a 1961 Olds shop manual plus a 1962 supplement .
They are available on E-Bay ;
https://www.ebay.com/sch/i.html?_fro...963+oldsmobile

borgerding

Thank you for the input. I will look closer for the port.
I do have the 61/62 service manuals including the Starfire supplement, but they dont show any port locations.

Charlie Jones

I looked at this myself . and I don't think there are any external pressure "ports " .
You should be able to remove the pan and the valve body and check the clutches for pressure leakage with air pressure from a blowgun .

borgerding

Thanks, Ill see about dropping the pan.

Charlie Jones

Boy ! Was I wrong .
I looked in my 1963 Motor's and I saw that there two pressure ports .
They are on the left side of the tail housing , just above the pan rail ;



Here is more information on " in car repairs " .
Including the pressures you are looking for ;

borgerding

Thanks Charlie,
Is that a model 10 roto-hydramatic "slim jim"?
I'm not sure, but it doesn't quite look like mine? I'm gonna crawl underneath my 62 Starfire and take a closer look.
Hope its the same, that would be a big help!

Charlie Jones

Yes , it is a model 10 " slim Jim "
Motor's simply refers to it as a " 3 speed " .

borgerding

Thanks Charlie, you are correct.
Just didnt recognize it.

Thdrbolt Ffxi

[QUOTE=Charlie Jones;1224183]Everyone dismisses the" slim Jim ' transmission .
Because , " the guys that know how to work on them are all dead " .

well I'm not dead I know how to rebuild a 61 to 64 Oldsmobile slim jim 63 Pontiac Slim Jim

Charlie Jones

[QUOTE=Thdrbolt Ffxi;1275972]That's great ! There are are only a handful of shops across the nation willing to work on a " Slim Jim " .
You are indeed one of the few . Tell us more about your shop and services .

borgerding

Thanks,
I’ll be in touch if I need slimjim worked on.

ripper27

I luck out had mine rebuilt by a young guy that he learned from his dad how to rebuilt them , use to slip when it got hot , needed a complete rebuilt , runs great now , you have to get use to the way they shift its so different from other trans