Correct Fluids for 1978 Cheorkee

[Santeh]

Hello all,

I took a quick look at other threads and did not see this information, thus if I missed it I apologize.

I have been making progress on my 1978 Cherokee as I just finished having a FiTech fuel injection system (with new pump) and Davis distributor installed as the Jeep was having a problem with its carburetor. I must say that even though the pumps are loud the Jeep drives very well now. However, when the systems were being installed I was told that I had several leaks, namely it needs an oil pan reseal, new power steering pump, and has a transmission leak. It will take a little time to address all the issues, thus I had a few questions:

1). What kind of engine oil would you all recommend for a '78 Cherokee? Is it better to go with a synthetic since the Jeep has ~126,000 miles on it?

2). It is my understanding that the Jeep does not share transmission and transfer case fluids. As such, is there a specific type of transmission fluid that is recommended for this type of vehicle?

3). Finally, what kind of power steering fluid is recommended? If I need to replace the power steering pump, will either of these work:

A). New pump: http://www.rockauto.com/en/moreinfo.php ... 90&jsn=422

B). Remanufactured pump: http://www.rockauto.com/en/moreinfo.php ... 90&jsn=420

Thank you, everyone!

[Cecil14]

Fill in your signature, that'll help us give you recommendations based on what you have.

Couple thoughts: first, grab your TSM from here http://oljeep.com/edge_parts_man.html. That will give you all the factory recommended fluids.

As far as engine oil...ugh. Everyone has their favorite brand/weight/chemical makeup/etc. I prefer Amsoil's ZRod oil. It's a high zinc oil that is supposed to help with flat tappet cams. 10w-30 is just fine for my motor. Bulltear also makes an oil a lot of people like, designed specifically around AMC engines. I probably wouldn't drop a lot of coin on synthetic oil in an old leaky engine. New build, sure. Synthetics tend to show every little gasket imperfection and will leak places a standard dino oil does not.

What transmission/t-case are you running? Each setup requires fluid unique to the components involved.

Power steering can go either of two ways: ATF or power steering fluid. Either is fine, but do not mix and match. If you're replacing the pump, then I would probably run ATF. Just be sure to flush everything out really well at that first fill.

Both of those pumps look fine? I believe you can also get a rebuild kit for your pump, or at least could at one time. I can't comment as to quality of the saginaw pumps, as I have not had one in a long time.


aa

[Santeh]

Fill in your signature, that'll help us give you recommendations based on what you have.

Couple thoughts: first, grab your TSM from here http://oljeep.com/edge_parts_man.html. That will give you all the factory recommended fluids.

As far as engine oil...ugh. Everyone has their favorite brand/weight/chemical makeup/etc. I prefer Amsoil's ZRod oil. It's a high zinc oil that is supposed to help with flat tappet cams. 10w-30 is just fine for my motor. Bulltear also makes an oil a lot of people like, designed specifically around AMC engines. I probably wouldn't drop a lot of coin on synthetic oil in an old leaky engine. New build, sure. Synthetics tend to show every little gasket imperfection and will leak places a standard dino oil does not.

What transmission/t-case are you running? Each setup requires fluid unique to the components involved.

Power steering can go either of two ways: ATF or power steering fluid. Either is fine, but do not mix and match. If you're replacing the pump, then I would probably run ATF. Just be sure to flush everything out really well at that first fill.

Both of those pumps look fine? I believe you can also get a rebuild kit for your pump, or at least could at one time. I can't comment as to quality of the saginaw pumps, as I have not had one in a long time.


aa

Thank you for the help and the links. I appreciate it!

Sheepishly, I am not sure what transmission and t-case I have, yet I understood them to be the original ones in my 1978 Cherokee S. Is there a way to check?

If it helps, I am in west central Florida which does tend to get rather hot. I am not sure if this might influence the choice of engine oil.

As for the power steering fluid, as I have only had the Jeep for six months I am not sure what was used before. Yet when I have the pump tended to I will be sure to use ATF (automatic transmission fluid, yes?). As for the pumps themselves, if they both look okay I will probably go with the ACDelco for, even though it is remanufactured, at least I am familiar with the brand name.

Thank you again!

[Cecil14]

Auto or manual? If manual, 3 or 4 speed?


aa

[Santeh]

Auto or manual? If manual, 3 or 4 speed?


aa

It is a 360 V8 that is automatic.

[Cecil14]

If it's original, it'll be a TH400 transmission and a QuadraTrac t-case. I believe the TH400 uses Dextron 3? The TSM I linked above will give specifics, though. It's nothing special, should be available everywhere. The QT fluid is available from BJ's: http://www.bjsoffroad.com/Quadratrac-Fluid_p_1596.html.

BJs also has a number of other hard-to-find service items for the QT.


aa

[Santeh]

If it's original, it'll be a TH400 transmission and a QuadraTrac t-case. I believe the TH400 uses Dextron 3? The TSM I linked above will give specifics, though. It's nothing special, should be available everywhere. The QT fluid is available from BJ's: http://www.bjsoffroad.com/Quadratrac-Fluid_p_1596.html.

BJs also has a number of other hard-to-find service items for the QT.


aa

Hello!

I looked over the manual for the 1977 Cherokee/CJ/Wagoneer via the link you provided and it notes SAE 20W-40 for the engine oil and ATF/Dexron/Dexron II for the transmission. I think I will go with the 20W-40, ATF, and TCL-1.

The only issue I am not sure on is whether ATF was previously used in the Jeep as I do not want to mix-match as you were cautioning me of...

Thank you! I appreciate it!

[Cecil14]

ATF has a nice reddish tint to it (assuming it's not burnt), while power steering fluid is more clear/brown if I remember. They're both relatively inexpensive, grab a bottle of both and compare with what you have now. Color, viscosity, smell, etc. I think you'll be able to get a pretty good idea which you have.


aa

[Santeh]

ATF has a nice reddish tint to it (assuming it's not burnt), while power steering fluid is more clear/brown if I remember. They're both relatively inexpensive, grab a bottle of both and compare with what you have now. Color, viscosity, smell, etc. I think you'll be able to get a pretty good idea which you have.


aa

Nice! Thank you! I greatly appreciate all of your time and advice!

[1979bettywhite]

Before you go replacing the pump, make sure to wipe everything down really well. Use some degreaser or some brake clean to make sure to get everything off. Get everything super dry, top off the power steering fluid and drive around for a bit. You want to make sure that leak is coming from the pump and not the lines. If it is coming from the pump, it will probably be leaking from the seal where the pump goes into the reservoir, most likely leaking from the bottom. Get a white paper towel and see what color your PS fluid is off the dipstick before topping off. Should be able to tell pretty easy there.

I just replaced my PS pump, it's a pretty easy job to be honest. Simple tools and a little time. Replaced it with a Reman from Napa. About $10 more than the Rock Auto ones listed, but I trust Napa and their warranty. If it were me, I would not spend the extra money for a new one.

You really only need to remove the lines from the pump, let them drain out and then remove the pump. You will have to swap over your studs from the old pump to the new pump if you use a reman pump, not a hard job. Just remember to use some teflon tape when reinstalling the ones in the reservoir, better to be preventative. You will need to pull the pulley off the old pump as well. Use the proper pulley puller, not a standard two or three arm puller. It will be a simple job if you use the right puller/installer. I borrowed one form O'Reilly's and it worked just fine.

Fill with whatever to the full cold line, leave the top off the PS pump and start the Jeep. Back and fourth with the steering wheel a few times and then recheck level, keep adding till the level stays constant.

[candymancan]

20-40w is thick as BEEP man... Why do you need to put that in ? stick with 10-30 or 10-40 especially in winter... that 20-40w if its cold out will blow up your engine.

I use 0-40 in mine.. Better flow on startup means better protection.

Dexron 3 in the transfercase and trans and 80-90 in the diffs.. and prestone the green stuff for coolant. Dexron 3 is what pretty much all GM transmissions use.. even modern ones today.

[1979bettywhite]

I agree 10W-30 is fine, and you could probably get away with 10W-40 just fine in FL. But just make sure to use something that still has some zinc in it. Oil type/brand/etc. might be the most debated topic out there. But I think most will agree on the weights and making sure to have some zinc as well.

I run 20w50 in my 258 in the CJ, but she is pretty old and tired, so it helps to quiet her down, pumps up fine on startup. Chief gets Castrol or Rotella 10w40, whichever is on sale. But always use a quality oil filer, napa gold or wix (basically the same thing). I am in GA, so mild winter temps and hot summers.

[Cecil14]

Dexron 3 in the transfercase

Great way to blow up a QT. Use the fluid I linked above.


aa

[candymancan]

How would dexron 3 blow up Qt unless this is some qt im unfamilier with. I only know the ones in ZJs that use a viscous coupler and use atf4 or dex3

I guess these ancient ones use open clutch packs vs sealed ones like in a viscous coupler ?

[HeavyMetalThunder_81]

How would dexron 3 blow up Qt unless this is some qt im unfamilier with. I only know the ones in ZJs that use a viscous coupler and use atf4 or dex3

I guess these ancient ones use open clutch packs vs sealed ones like in a viscous coupler ?

The original '74-'79 Borg Warner 1309/1339 Quadratrac has nothing in common with the later New Process "Quadratracs" other than the name. ATF in a Borg Warner QT will kill it in no time, they require special fluid.

As for transmission fluid, any Dex III or above will work.

Oil, I like 15w-40 Mobil Delvac. The extra zinc in most diesel oils is beneficial to our flat tappet camshafts. It doesn't really get cold here so the heavy weight doesn't hurt anything.

Power Steering Fluid, I don't like ATF in my Saginaw power steering pumps. That is just personal preference, though. If it were me, I would find and fix the leak. Then I would flush all the fluid with fresh power steering fluid.

[Santeh]

Hello all!

Thanks again for all of the information and your thoughts!

I went with 10W-40 for the engine oil and ATF for the transmission/power steering. Yet I am taking the Jeep in hopefully soon to fix the oil and transmission leaks, as well as install a new power steering pump (I think I will get this one: http://www.rockauto.com/en/moreinfo.php ... 90&jsn=422). I have not bought anything yet, but I was going to get the TCL-1 for the transfer case.

As for my oil choice, the 20W-40 was something I got from the Jeeps owners manual yet I was surprised by the book stating that if driving at highway speeds one should avoid 10W-40. Thoughts?

Thank you again!

[candymancan]

How would dexron 3 blow up Qt unless this is some qt im unfamilier with. I only know the ones in ZJs that use a viscous coupler and use atf4 or dex3

I guess these ancient ones use open clutch packs vs sealed ones like in a viscous coupler ?

The original '74-'79 Borg Warner 1309/1339 Quadratrac has nothing in common with the later New Process "Quadratracs" other than the name. ATF in a Borg Warner QT will kill it in no time, they require special fluid.

As for transmission fluid, any Dex III or above will work.

Oil, I like 15w-40 Mobil Delvac. The extra zinc in most diesel oils is beneficial to our flat tappet camshafts. It doesn't really get cold here so the heavy weight doesn't hurt anything.

Power Steering Fluid, I don't like ATF in my Saginaw power steering pumps. That is just personal preference, though. If it were me, I would find and fix the leak. Then I would flush all the fluid with fresh power steering fluid.

diesel oils have less calcium then gasoline oils do.. Gasoline engines produce more acids that cause wear and thus gasoline oil is formulated for it.. Diesel oil like rotella have actually removed their gasoline certification from the bottles.

Just saying. I use gasoline oil but with rislones ZDDP suppliment. Even diesel oils have low amounts of zinc in them today

[nograin]

Hello all!

Thanks again for all of the information and your thoughts!

I went with 10W-40 for the engine oil and ATF for the transmission/power steering. Yet I am taking the Jeep in hopefully soon to fix the oil and transmission leaks, as well as install a new power steering pump (I think I will get this one: http://www.rockauto.com/en/moreinfo.php ... 90&jsn=422). I have not bought anything yet, but I was going to get the TCL-1 for the transfer case.

As for my oil choice, the 20W-40 was something I got from the Jeeps owners manual yet I was surprised by the book stating that if driving at highway speeds one should avoid 10W-40. Thoughts?

Thank you again!

You're misreading, or maybe looking at something different. I'm looking at page 99 of the '77 Owner's manual from Tom Collin's website.
20W-40 was ONLY for operation when the outside temperatures are above 40* F
10W was ONLY acceptable when temperatures were expected to be below 0* F.
Its unusual to see just a W grade. We'ld have to check the specs for mid 1970s but broadly speaking, W grades did not have hot engine viscosity requirements.
Contrast that with 5W-30 or 5W-20. These multi weight oils met the 5W cold temperature viscosity and the high temperature viscosity limtes for a 30 or 20 grade oil. With either 5W-20, or 5W-30 AMC could be sure that hot oil would still have viscosity properties needed.

Oil viscosity changes with temperature. Those grade numbers are not viscosity. They are specifications for viscosity at two temperatures. A cold engine's oil is no where close to the viscosity that will really lubricate well under load and at high rpm. The 0W, 5W, and even 10W- multigrade oils are just much better cold than a straight weight.

Back then a 10W-30 was probably the best all around choice. 10W-40 for hotter climates and engines that were a bit worn. For example if the oil pressure gage indicates lower oil pressure on long hot runs. I like to see 50-60 psi on the highway once warmed up.

[Fast Eddie]

I agree Nograin! I just dug out my 1979 Jeep owners manual and it states:

Lowest temp Anticipated : Above + 40 deg F. SAE 10W-30, 20W-40, or 10W-40

Above 0 deg F. SAE 10W-30 or 10W-40

Below 0 deg F. SAE 5W-20 or 5W-30

Obviously some of these grades are not available today, but I think everyone gets the idea!! 10W-30 would be your best starting point at least in most states....

Hope this helps!!!

Oh, and I also get the idea of the added ZINC for Flat tappets, but that is critical for a flat tappet mechanical cam, should not have as big an issue on hydraulic cams...IMO

[Cecil14]

I agree Nograin! I just dug out my 1979 Jeep owners manual and it states:

Lowest temp Anticipated : Above + 40 deg F. SAE 10W-30, 20W-40, or 10W-40

Above 0 deg F. SAE 10W-30 or 10W-40

Below 0 deg F. SAE 5W-20 or 5W-30

Obviously some of these grades are not available today, but I think everyone gets the idea!! 10W-30 would be your best starting point at least in most states....

Hope this helps!!!

Oh, and I also get the idea of the added ZINC for Flat tappets, but that is critical for a flat tappet mechanical cam, should not have as big an issue on hydraulic cams...IMO

I have seen all of those weights available regularly for as long as I can remember? Not all are really pertinent, but certainly still available.

As to the zinc...tons of wiped out hydraulic cams in the last decade or so, as oil formulations have started to change. Whether or not that is directly attributable to the lack of zinc? I've seen a lot of arguments on both sides of the fence, but the general consensus I have seen is that cams tend to last longer with higher zinc formulas.


aa