Transmission/shock absorber Oil
 

The manual for my '34 Ford V8 calls for summer oil in the transmission of 260 SAE. I can't find any. In another place it calls for 160 in summer. Is multi viscosity ok? Also, what to others use for fluid in the shock absorbers?

John Irving

Re: Transmission/shock absorber Oil
 

The main issue in transmissions is the "yellow" metal issue. You need to use a transmission lube that is compatible with the yellow metals it contains. GL-4 is considered safe, some GL-5 lubes claim to be safe, but I have my concerns and would stick with the GL-4. Mulit-viscosity lubes are fine (better in my opinion).

Not sure if the source you are looking at is using the older ISO VG rating or not, but if it is 160 - 260 would equate to around SAE 90, which is about right. To some extent it depends on how you like the shifting qualities, the viscosity of the transmission fluid changes the way the transmission "feels" when shifting it.

Re: Transmission/shock absorber Oil
 

Owners manual calls for 110 in winter and 160 in summer for the transmission. I have been using NAPA Sta-Lube SL24238 SAE 140 in the trans, diff & steering. It is GL-4.

Re: Transmission/shock absorber Oil
 

Regarding your shock absorber's, three types of fluid were used by Houdaille; Mineral oil of a Hydraulic Type (viscosity unknown but often guessed at) Castor Oil or Glycerine. When refilling the shocks place them in the same position as they are on the car with the filling hole slightly to one side. This prevents the shock from being overfilled. To check tension use a Spring Balance scale, place the shock body in a vice or on the car, attach the scale to the hole in the shock lever or arm and pull the lever with the scale. The correct reading is 70lbs.

Re: Transmission/shock absorber Oil
 

I use 10wt hydraulic oil in my shocks. I think you will get lots of opinion but it works for me. take shock off, put in vice and attempt to drain any oil out--sometimes I try to flush out shock with even thinner oil like MMO

Re: Transmission/shock absorber Oil
 

So what type of oil should I use in the houdaille shocks on my 1946 pickup?

Re: Transmission/shock absorber Oil
 

10 wt hydraulic jack oil