Pre-Buying inspection

[ZeMax]

Hi guys, so I've been on the market for a small Class C and I've stubbled upon a 1986 GMC Apalache 24 feet. Now my google-Fu wasn't able to find anything about this model. I know for sure that it as a 6.2 Diesel in it mated to a 700R4 :puke:

The transmission went through a full rebuilt 2 years ago. Yay ! Really didn't feel like trying to drop it from that thing.

The engine as 285,000Km / 177,000 miles. Reading the forum sounds like this engine could still be in good shape and it also helped me have confidence in that engine. One thing is for sure if I end up buying the Camper I'm ordering those nice manuals.

Could not find a shop in the area where the camper is being sold to do an inspection for me, I'll have to do it myself.

I'm an aircraft mechanic by trade which make me quite ignorant on Diesel engines but that allows me to follow procedures really good :) So far I've gathered those item for me pre-buying check list:

- Open radiator while engine cold. Check for bubbles once it as started
- Open oil filler cap once hot. Check for "choo choo" type smoke
- Oil seepage is tolerable. Oil leak are not.
- Seek help for further things to inspect.

Really stoked about this project and getting a gutless Diesel !

[Yukon6.2]

Hi
Try to be there for a cold start...
If everything in the starting system is good it should twist off with minimal smoke and cranking.Make note of smoke color if any.

[JohnC]

I'm an aircraft mechanic by trade which make me quite ignorant on Diesel engines...

Check to see when the next hot section inspection is due. ;)

[Robyn]

I am suspect on the tranny being a 700R4 in a 24 foot motorhome ??????

The 700R will never live hauling around that house

Should be a TH400

The 6.2 will tear up a 700 in light rigs like Blazers and 1/2 ton pickups....

Somebody could have swapped out the 400 and installed the 700, but this is a really bad situation if indeed there is a 700 in the rig.

Here are the shapes of the pans on the 700 and the 400 piccy's

Look at the gear box in the rig and compare to the pics.

IF IT INDEED HAS THE 700R...PASS ON THE THING UNLESS YOU WANT PAIN AND SUFFERING :(

[convert2diesel]

A bigger concern I would have is the mileage. Yes these engines can go for a long time with good maintenance in a truck but 177K in this application is the equivalent of over 300K in a truck.

Have driven a number of these rigs over the years and they were indeed grossly under powered. Even with aggressive gears, on the flat, you are talking at least 75% power to keep these rigs at highway speed. In other words, this engine was humping it all the time.

Agree with Robyn. If it has the 700R4, even if all the heavy duty parts were included in the rebuild, just the overdrive would be putting undue strain on the engine. At the very least, find a good 400 and use that. A little noisier but far better on the engine.

Bill

[Robyn]

My concern was not the engine...but the 700R tranny is a tiny little gear box
(Components such as clutches, planetary gear sets and such are just waaaaaaaaaaaaaaay too small to handle the size and weight of a 24 foot Motor home)

The deep low gears in the 700R are a great launching tool, but that's where it stops.

The main input drum/clutches are even too small for an aggressively driven K5 Blazer.

The OD would be fine for flat land running under some conditions, but as mentioned the 6.2 is just way under powered.
The torque converter is way too small internally and heat is going to be a big issue on a grade.

I built several 700R boxes over the years and put the best parts the aftermarket could supply and to the very last one they failed in one way or another.
Not if...just when...and it's never in a handy place.

I rented a 30 foot Class A once with a 6.2 in it...OMG ...A kids pedal car with a 4 year old could pull away from us on a grade.....

The combination was a bad jump when the factories did it, and it's still a bad jump, even with a TH400 box

The rear gears were likely 4.56:1 and the poor little 6.2 is running balls to the wall all the time just to try and keep up...

[ZeMax]

Thanks for the input Guys.

The tranny was indeed a 700R4. Was rebuilt and beefed up by a shop that as a great reputation. Cold start, engine was running so smooth. 0-60 in the 20s :D

But in the end, the Beds were too small. I hate my life.