[flyfisher]

So I bought my wife's Jeep TJ second hand and changed all the fluids within four months. I had already bought all the fluids from my usual jobber except the synthetic for the diffs. They don't stock synthetic diff oil because they recommend using conventional oil and changing it more often than recommended. (A practice that my brother swears by.)
I went to another jobber and they had the Chrysler recommended 75W140 synthetic. They were asking $20.00/liter. I was hessitant to say the least about spending that much money so they got out the charts and explained why Amsoil was the best oil to use. I wanted only the best for the Jeep and the Flyfisher was fished in and I came home with three litres of this junk.
It's 16 months and about 30 000kms later and this oil looks like conventional 80W90 with 230 00 kms. The magnetic drain plug has 1/2 inch of gear on it, I can just imagine what the bottom of the diff looks like.
I've used other synthetics in my Jimmy, usually a lot cheaper than this stuff, and they have never been so broken down as this stuff with three times the wear on it. I'm going back to conventional oil in my diffs and Amsoil had their one chance with me and blew it. I will never recommend or use another Amsoil product again except the Power Foam--even then only as a last resort.
I'm just fuming because to top it off the front of the transmission is leaking bad (probably the input shaft seal), The 4WD linkage is squeaking because a grommet has fallen off, and the front fender is starting to rust through. This is a '99 Jeep.
I expect a little more from my vehicles I guess. My wife hates it when I compare it to my '88 Jimmy that has been nothing but reliable throughout it's 465 000 kms--she's right, you can't compare GM to Chrysler.

 

[Ghetto Jet]

This thread was really hard to understand. Am I reading correctly: you ran 75w140 for motor oil?

 

[flyfisher]

Gear oil in the differentials

 

[Ghetto Jet]

Ok! I forgot the jeeps rearend have a magnetic drain plug. Did you run Amsoil in the motor also?

 

[bud-23]

In the Jeep rearend. ( can I say rearend? )

 

[Ghetto Jet]

I didn't think i could, so I said diff. But if your going to say it, then I will to.:thumbup:

 

[flyfisher]

Ok! I forgot the jeeps diffs have a magnetic drain plug. Did you run Amsoil in the motor also?

No. I usually run a bunch of other synthetic brands of oils. Mobil 1 seems to work the best. I've done a bunch of research on synth. oils and as best as I can tell the only major difference is the marketing. An aquaintance of mine always runs Amsoil in his race engine. His engine rebuilder says it stains the metal red, and has a tendency to build up in the oil passages. Just hearesay--Don't know for sure and don't care to find out.

My Jimmy was running Mobil 1 synthetic for about 280 000 kms out of 420 000 kms. I'm not sure what finally did in the original engine (I didn't bother to fix it, I just changed it) but it was probably a dropped valve or spun timing chain. Any engine oil that can do that kind of kms is alright by me.

 

[SAATR]

Far as Chrysler gear oil, we've always used nonsynthetic for the differential services. Boss worked for Chrysler for three years as a mech., and he never said anything about running synthetic in the diff., BUT you do have to run the Chrysler recommended synthetic for the manual tranny, lest you waste the tranny. Unless it's limited slip or something special, standard gear oil is what they use, is what we use. Lesson is, use what you know works, and let somebody else do the trial and error for ya.

 

[flyfisher]

Far as Chrysler gear oil, we've always used nonsynthetic for the differential services. Boss worked for Chrysler for three years as a mech., and he never said anything about running synthetic in the diff., BUT you do have to run the Chrysler recommended synthetic for the manual tranny, lest you waste the tranny. Unless it's limited slip or something special, standard gear oil is what they use, is what we use. Lesson is, use what you know works, and let somebody else do the trial and error for ya.

I'm a mech. eng. tech so I understand that a lot of calculations and testing is required to determine the best lubricant for the application and it's usage. I got the recommended lubricant specifications for the differentials from the Service Manual for the 1999 Jeep Wrangler (TJ). It reads:

"...The lubricant should have MIL-L-2105C and API GL 5 quality specifications.
Lubricant is a thermally stable SAE 80W-90 gear lubricant.
Lubricant for axles intended for heavy-duty or trailer tow use is SAE 75W-140 SYNTHETIC gear lubricant..."

As far as the transmission, both the AX5 and the AX15 manual transmissions recommended oil is Mopar 75W-90 or equivalent. No mention of synthetic.

My choice in the viscosity of oil was correct. The bottle did bear the API GL 5 marking, I don't remember if it met the military spec. as well. The point I'm trying to make is that if Chrysler recommends this viscosity and API spec. then it should function, worry free, for at least as long as conventional oil. Last night's discovery has me worried, and I'm blaming the manufacturer of the oil.

 

[Beenaway2long]

From the "For What It's Worth" file:

I use the Amsoil shock oil for rebuilding snowmobile shocks. I do close to 500 a year. I have had ZERO oil related problems. When using Fox, Showa, Maxima, Thorolixir, and on & on, I used to get my share of problems. I don't see the Amsoil break down as much as the other brands. Some stuff comes out smelling like pee. (Burnt)
I also raced snowmobiles on asphalt. By MISTAKE, I used a Ratio-Rite cup that said 50:1, but I didn't see the 2.5 gallon title. Consequently, I was running 100:1 when I mixed the oil in a 5 gallon container. I ran 5 gallons of fuel through this race sled @ 135 mph. I was shocked when I saw the graduations in the mixing cup, then proceeded to rip the motor apart that evening. All the components had a nice oil film covering everything. SWEET ! The skirts looked like NEW. I told my dyno guy about it. He had me scheduled for 2 weeks later, so he said to bring a batch of 100:1 and 50:1. We also tried a Ficht fuel catalyst pellet, and 3 other fuel/oil combinations.
Results: 100:1 was .3 horse better than the 50:1. After that, the other fuels were up to 3 horse less. (OEM Arctic Cat oil) Ficht didn't seem to do much. Maybe because the fuel was from a sealed drum? Normally, he said they work great from pump gas.
I use their air filter and oil in my truck with ZERO problems.


But thats just MY experience.

 

[SAATR]

I understand that you are upset with the oil company, I was saying that I wouldn't have run a product that I wasn't familiar with, that's all.

As far as the transmission goes, I was wrong. I was thinking of the NV3500 manual tranny, which does spec synthetic gear lube and nothing else. Sorry for the confusion.

 

[killerformula]

lol, I'd pit my jeep against any jimmy any day of the week. More power, lighter, better axels.

As for the last chrysler I built, 360 mopar, tore it down after 150,000 miles. Didn't need it. Not a scratch on the crank, double timing chaing (yeah, that's right, double, when's the last time you saw a double timing chain in a chevy truck?). Rods were heavy... but then again they were about two inches thick of solid steel. Block had higher nickel in it than most chevy blocks, too.

lol, what a rant.

OOps! Sorry about that! Don't get me wrong dude, I just built a 388 for my firebird! lol, anyway.... As for the diff, I don't think you can blame it on that if you're also blaming the oil. Those chrysler rears are tough.

K

 

[flyfisher]

As far as the two stroke oil, can't comment. My sled's been hanging for a couple of years now. One of the guys I used to sled with swears Amsoil is what caused his sled to seize. He's got a formula 3 and the first time out with Amsoil he was dragged back to the trailer after about an hour. Don't know, just doesn't sound good coupled with my own experiences with their products.

Killer, I'm talking about a 2.8 6 cylinder compared to a 4.0 6 cylinder. The 2.8 has proved it's self, the 4.0 is about 200 000 kms away from proving it's self. So far, so good. With the exception of a cracked exhaust header, no problems. (I welded the header about a year ago, and it's still together, so no problem.) I'm not getting into a Chrysler vs. GM thing, it's just something to wind up the wife. Personally, I like the longer wheel base for driving on the road where most of my driving is done. The Jeep gets a little squirrely on washboards or icy, slippery roads. The Jeep will get it's self out of a ditch better than a Jimmy though. Really, Dana makes a jim dandy (there, I didn't use colourful language) axle. I don't blame any component of the Jeep's driveline, just the metal filled black tar that some people want to call oil.
I do love the Jeep. There's nothing better than driving around with the top down and the doors off for the whole two weeks of summer we usually get around here.

My 350 that I had in my S-15 had a double chain. It was originally out of a police cruiser, so I know it's not a fair comparison.