Dumb things in the desert

[Ed in Montana]

Three weeks ago when I was down in Death Valley, I did something dumb. I drove the SMB in 4WD for about 50 miles on dry pavement, and when i stopped, I noticed that the front differential was spatterring oil around the left front underside.

I know you should be able to notice if the rig is in 4WD high, but it was hard too when driving into a howling headwind. Luckily, I never really got up above about 45mph, due to a combination of the 4WD and the headwind.

So the question is, what is the oil in the Dynatrac front axle? And can you replace it with a synthetic oil like from Amsoil?

I checked everything in my SMB documentation, but no clue on what to use in the front diff. I did check the Atlas transfer case which foamed a little from the 4WD high, but only lost maybe a quarter inch of fluid on the sight tube on the case.

Any suggestions?

[EMrider]

Originally Posted by Ed in Montana

Three weeks ago when I was down in Death Valley, I did something dumb. I drove the SMB in 4WD for about 50 miles on dry pavement, and when i stopped, I noticed that the front differential was spatterring oil around the left front underside.

I know you should be able to notice if the rig is in 4WD high, but it was hard too when driving into a howling headwind. Luckily, I never really got up above about 45mph, due to a combination of the 4WD and the headwind.

So the question is, what is the oil in the Dynatrac front axle? And can you replace it with a synthetic oil like from Amsoil?

I checked everything in my SMB documentation, but no clue on what to use in the front diff. I did check the Atlas transfer case which foamed a little from the 4WD high, but only lost maybe a quarter inch of fluid on the sight tube on the case.

Any suggestions?

This is the Amsoil product I used in my front and rear diffs.

http://www.amsoil.com/storefront/svo.aspx

And FWIW, I didn't know that driving in 4wd high for long distances was a no-no. In fact, I've done it myself a few times. On each occasion, for at least 20-30 miles at 65mph. No leaks from the front axle.

I asked about this when I picked up my van and was told (paraphrasing here) "We've had these vans up to 85mph in 4wd down in Mexico many times, don't worry about it........"

[jage]

Originally Posted by EMrider

And FWIW, I didn't know that driving in 4wd high for long distances was a no-no.

You missed the part about "on dry pavement".

I've heard of the dynatrack spitting fluid because the hubs were locked for a long time, it got hot, whatever. It might be a thread on this board (scatter maybe?) Use the search, Luke!

Anyway leaving it in 4wd on dry pavement- damage is done by the wheels not being able to slip, so the drivetrain differences between front and rear cannot be relieved. Worst case scenerio is backing up on a turn, never done it in the SMB but in the Jeep it will buck the Jeep as the tires let go. So turning creates a slight differential in the tires.

The second thing is actual driveshaft rotation which can be negatively affected by: tire size, gear ratio, tire pressure, excessive wear. The rule is you're ok if you're within 10%, however that is for being offroad not dry pavement.

Still if things don't add up significantly (as in backing and turning in 4wd low) you won't have problems. It puts unnecessary stress on everything, but chances are you didn't do any major damage as the Atlas is fairly bombproof. Top off your axle and listen for any new noises... and double check next time.

[lowracer]

Dumbest thing I ever did in the desert? Don't pet the cholla cactus thinking they're cute and fuzzy. They look like it, but they're not.

[EMrider]

You missed the part about "on dry pavement".

Nope, that is exactly what I was referring to. I get the impression that this is not a good habit.
R

[deminimis]

Has anyone here rigged up a green light to indicate when the vehicle is in 4x4? I noticed a wire in the engine compartment labeled "4x4." The wire, my guess, is for an indicator light, but it isn't nor does it appear to have ever been hooked up to anything. Was thinking a small green led in the dash would be better than nothing and would certianly help us remember if we leave the rig in 4x4.

[oclv]

I think that would be easy. On my list of things that Salem Kroger is doing on my 4x4 converson was a 4WD indicator light. I will see it, hopefully, on Friday. oclv

[daveb]

mine came with an indicator...it's so bright the light is kind of annoying at night. I was thinking of changing it but because it's by the parking brake release I decided to leave it where it is........easy to see in daytime

[deminimis]

Cool. Will pull out the test light and see if the wire is hot or not tonight.


Ed, check with Dynatrac about recommended fluid. Very quick response time and helpful.

[Ed in Montana]

Thanks for the advice folks. I will check with Dynatrac before I order any oil, and the Amsoil reference is very helpful.

I have that green 4WD light which only comes on with four wheel low, not with four wheel high.