OK, now that I have everyone's attention.

Vehicle: 94 Grand Cherokee Laredo 4.0L All the time 4WD.

Here is my question, how is the transmission operated?

I am being told that the lever on the left should be in neutral when driven is this correct? I am asking to verify that my son did not totally screw up his differential and run it in 4H instead of neutral. Confirmation or denial will be helpful.

 

Do you have an owners manual?

 

Yes and no. There is one in the glove compartment of the truck but, the truck is 4 hours away from me. I spoke to my son and he is stating that "N" is to disengage the drive for towing and that if you put it into "N" the truck will go nowhere.

I am trying to confirm or deny this for warranty purposes on the front differential that got toasted. I am familiar with normal 4WD systems that have a 2 wheel drive setting not this type of set up.

 

Your son is right about it not moving in neutral but it should not be ran in 4H on dry roads unless you have a NP 242 TC. Then it should be in part time 4H

 

OK, so I guess I'll let him live another day. I don't suppose someone can take a picture of the instructions that are on the back of the visor and post them? I would also like, if possible, a scanned pdf copy of the specific operating instructions in the owners manual.

This would be most helpful when I respond back to the guys who sold me the bad front differential. I've asked the shop that has the jeep to do this but I don't know that they are that technically savvy as it is a very small shop and they may not have the ability to do this.

 

The lever on the left is for your transfer case. Likely an NP249 "Quadra-Trac". Putting it in neutral disengages the transfer case for towing so... no. If you put "the lever on the left" in neutral you won't be going anywhere. It should normally be in the forward most position (4hi or Full-Time, something like that), neutral for flat towing, and 4LO for off-road, slippery surface.

 

I definitely feel better about the situation; thanks for all the feedback. Now I get to fight with the people who sold me the front differential assembly.

 

I should have been more clear on 4LO. It's for crawling and getting unstuck, not for any sort of normal driving. Never use on grippy surfaces.

 

So, what's the problem? What's wrong with the "front differential assembly"?

 

From what the tech said on the initial eval, the backlash was set improperly and too tight which caused the gears to overheat. This boiled out the fluid and blew the seals ultimately cooking the gears.

My son and I installed the complete assembly and only changed the fluid and cover gasket. My son is a trained automotive tech out of UTI. The company who sold me the assembly is trying to come up with a way to put blame on my son so they don't have to honor the warranty on the assembly.

 

Let me guess. 4 Wheel parts?

That brings me to wonder why a Trained Automotive Tech would purchase a complete assembly.

 

I was wondering the same thing, but strange things happen when parents are paying for stuff... possibly for the warranty?

 

Warranty and lack of tools. He is now working for Air Wisconsin basically doing all the ground work i.e. baggage, plane parking, de-icing etc. He is getting paid a lot more than when he was working at an automotive shop so didn't have the access to the tools needed.

The original plan was to pull the diff and transfer it but as we looked into the requirements, we determined that neither of us had the tools necessary. I mainly work on classic European cars, I have an MG, Porsche and Mercedes that I have done work on bumper to bumper with the exception of re-building a differential...yet. I tend to accumulate tools based on the work I do and haven't had to rebuild any diffs yet although I will be in the near future with my MG.

Since I was paying for this I wanted to make sure that there was a security net which is where the warranty comes in. I would have preferred to just swap out the diff but that wasn't a COA that was manageable at the time. Ich denke nicht der Differential Ich kaufte ist Scheisse!

 

Ya lost me at the end there.

Keep on them about the warranty.

 

Sucks. Hindsight is 20/20