Hi,
New member here and have just acquired my first Jeep. Its a 1999 GC with 71K miles.
I put all new brakes and shocks on and changed the transfer case to the correct Mopar stuff.
Had a raidator leak and the oil pan was way too rusty with a small leak on the bottom. I brought it to an indy mechanic that was highly recommended as I did not want to get into the oil pan issue myself.
I planned on changing the diff fluid on both of them to Royal Purple and had bought 4 Qts. Being at the shop for the other issues I asked his to change the fluid which he did. Being that the Jeep came to me without any service history I wanted to change all the fluids to start. When I got home yesterday I looked underneath and noticed that the diff covers had not been removed. The w/o says flush and fill both diffs. Is there any way to flush and fill without removing the cover? I know you can suck it out and refill but is that really an acceptable method?
Thanks for any thoughts.
Tom

 

Sucking it out doesn't get all the old fluid out and you should inspect the gears anyway so take the covers off. They don't use gaskets unless someone has put one on and they are generally sealed with RTV silicone.

When I bought my 2000, it had 125K on it so I really wanted to know if everything was all right. I took the covers off, flushed them out with kerosene with paper towels under them to watch for metal fillings, checked the gear backlash and wear patterns, cleaned and wire brushed the covers, sealed them back up, and refilled with 75W-140 Synthetic gear oil because I live in a cold climate and pull heavy loads. But that's me and I'm fussy.

Even with all this care at 215K miles, the rear carrier assembly cracked and the planetary shaft tore out destroying the whole diff! No warning, just BAM!

 

Yeah I think most places will just suck out the old and put in the new without removing the covers unless you specify. More money in labor of course, but it should be done once in a while as Dave said to inspect everything.

 

Thank you both for the thoughts.
I did tell him that I had just bought it and wanted to change all the fluids to see where I was at but do take the blame because I did not specifically ask to have the covers removed and cleaned and inspected.
I supplied the Royal Purple and he charged $80 for a suck and refill which I think is high. What is the color of RP, I checked both diffs and the fluid was a very light tan in color.
He did a radiator change and flush with G-05 that I specified and when I asked if he diluted it with distilled water he said no you really don't have to do that with the good antifreeze we have today. Not sure I be going back for future maintenance that I need to farm out.

 

Okay, Chrysler didn't switch to G-05 (HOAT) coolant until 2001 and any vehicle built previously would have been delivered with EGW (Ethylene Glycol) (The old green stuff) in it. It's okay to use G-05 in earlier models as long as the system is thoroughly flushed before using because they shouldn't be mixed together. It's also possible the previous owner switched already.

Anti-freeze coolants today come in 2 different styles, concentrated and premixed. The premixed solutions are designed to provide the best thermal protection for both hot and cold applications and are mixed with distilled or filtered water. There's not much difference in price per gallon either.

HOAT stands for Hybrid Organic Acid Technology and is designed to reduce corrosion in systems with aluminum components, such as engine blocks and heads, and radiators. IDK, but I'm a 73 year-old dinosaur and EGW has worked for almost 100 years as a coolant in all types of engines and as long as it's changed on a regular schedule shouldn't be a problem. But that's my personal opinion.

BTW, which engine do you have? The 4.0 straight 6 or the 4.7 V8? Also, most shops charge $85/hour or higher, depending on the type of work they do. Dealers are astronomical! My mechanic is a Good-old-boy classic car and hotrod freak and only charges me $65/hour because I always pay in cash! That way it doesn't go on the books! LOL! He's as old as I am and only works for something to keep him busy. He doesn't have a sign on the road, but has enough business to require appointments for work. His best customers are for State Inspection. He'll scan your system to tell you if it will pass or not BEFORE plugging it into the State hotline.

 

OUCH!

 

Dave, thanks for the info. It has the 4.7. I just wanted the best chance of not having to install a new heater core and the use of distilled water I thought was normal in doing a full flush at least thats the way I have done it for the past few decades.
They call for the HOAT in the 4,7 now so that why I switched as it had the green stuff in it when I bought it. It had just had an oil change when I bought it. I asked what type of oil it was and the person I bought it from, not the original owner from new, said whatever Jiffylube uses.
First thing I did was change it to Mobil 1 5-30 and a new filter. I take good care of my vehicles and keep them for a long time. My last car, a 96 Saab had over 300K on it and never had the head off and original turbo. My truck a Chevy 2500 Duramax diesel is well over 200k and runs just fine, lawn mpwer and wood chipper are all on synthetic oil. I guess I am too **** but I enjoy the feeling of driving a vehicle that has the best care and products.

 

Likewise, I like a vehicle you can depend on. One that I could take on a 600 mile trip and not worry about. Proper maintenance is the way to have that. Unfortunately, my old girl is getting questionable at this point with 235K miles on her. The engine is okay, but the trans I worry about. It's original but has had the proper care.

Overheating is a death nail for a 4.7 so be very careful in that respect.