I don't have an owner's manual for the 91 Ramcharger, I'm looking for the recommended fluid to use in the power steering.

My 92 Dakota says ATF, but it is rack and pinion.

I've used ATF in other 1st gen and older Mopars, but this is going to be a new steering box, pump, and lines, so I figured since I'm starting from scratch I may as well use what it called for.

It's primarily a winter and crappy weather beater, so the best flowing fluid for cold weather is best option.

Ive always used nothing but mopar brand ATF in any mopar system

It would help if we knew what year, make, model, and engine size??

Updated, 91 Ramcharger.

Engine is 318 if thats of importance for some reason.

Identifix/ Direct hit, which uses mopars Factory info. Lists Mopar P/N 04883077 (MS-5931) Power steering fluid.

I am not at my business right now. But I would have to check on my Power Steering fluid bottle and my Synthetic ATF fluid paper work. They both have a list of the specs or fluid specs that they cover. I could check tomorrow morning, and post back here.

That would be great. The truck goes under the knife early next week.

Power steering fluid.

other than one specific year (forget exactly when) that Mopar said to use one or the other/ but specifically said NOT to use the other fluid between the 2, it was much newer than you are talking.... but the next year, they flip flopped back the other way. otherwise I have seen them say to use one or the other, with the other as an "acceptable substitute".


I would say to use which ever you have on hand and keep it that way..... not inner mixing the 2, would be the more important factor. If you start with ATF, keep it ATF as long as you continue to own it.
same thing can be said about "power steering fluid" if you wanna swap fluids, drain and flush the old stuff out, and run 100% of one or the other. all the time.

Suppose to be power steering fluid that meets Mopar SPEC # 5931 .. Going to have to look on the back of some power steering fluids available in your area...

Mopar had Power Steering Fluid for years

But when the ATF improved to ATF +4 most of the old parts numbers for PS fluid superseded to that

So your 91 Ramcharger would work fine with either

Use actual power steering fluid like it was originally intented for.
Even GM stuff that was quick to change to ATF in the 80s, it seems they used that in rack and pinion and power steering fluid in the older style pumps and boxes.

Generally, ATF+4 and power steering fluid should interchange in modern cars.
Power steering fluid has chemistry to reduce noise, so in general it is preferred.
With older models, stick with PS fluid only, to reduce noise.
I worked at Mopar for a few years, learned this there.
Mark

x 99 .... R E A L power steering fluid! .... unless you are in a climate that is REALLY cold !

Thanks all.

I got the steering box, hoses, lines, etc. changed yesterday, and the system now has fresh power steering fluid.

I have always used https://www.amazon.com/CRC-SL2641-Power-Steering-Fluid/dp/B000M8Q1ZS
It was fine in my old stuff. I`m not sure about a 91 vehicle though.

Mopars with Saginaw pumps and 72-93 trucks which have Saginaw boxes the GM cold weather P/S fluid works great. Gets rid of that whine they get with regular p/s fluid.