Safe to drive with broken sunshell/sungear?

[honkon]

I'm looking at buying a '97 Yukon, which, according to the ad, slips in reverse. Guy told me the sungear is broken, but I didn't ask if he had somehow verified this or knew for sure. When I was looking at it, I put it in drive/reverse and rolled it a couple feet multiple times, each time it went into reverse without fault and made no strange noises. Truck was stone cold when I got there.
I plan to take the trans apart and try my hand at replacing any broken/worn parts. Would driving the truck about 80 miles home on the interstate with a broken sun shell or sun gear be destructive?
I'd imagine it most definitely would be if the sun gear is actually broken, because doesn't it usually take the reverse planet with it? Having the pulverized remains of the teeth of the planet and sun gear floating around in the fluid for that long would surely be awful for the rest of the trans, which is well worn anyway at 173k.
I didn't check the fluid when I was there, so I can't comment on what might be floating around in it. This issue really occur to me at the time because I had no idea what a sun gear was until I got home and googled it.
Thanks.

 

[seanb98]

With a vehicle at an entirely unknown level of drive ability, I personally wouldn't do it. If you don't have a trailer, or a buddy with a trailer you can rent one pretty reasonably. Probably a better idea since you have an unknown status vehicle and nobody likes being broken down far from home trying to figure out what to do. Better to get it home, then drop the pan and do your own diagnosis from there.

That is assuming the price you are buying this vehicle is worth it in the first place.

 

[Biggershaft96]

i would at least have a buddy with a trailer ready to come get you. I personally wouldnt drive that far with a hurt 60e but if you think it'll make it then go for it. What's the worst that could happen right? Trans needs rebuilt anyway.

 

[honkon]

Thanks for the input.
If I end up with it I'll probably go get it on a Friday afternoon so I have all afternoon and night to limp it home. If I explodes I'll just have to deal with it.
If it is grinding and just seems generally unhappy about being operated I might have to rethink my plan.

 

[big green96]

My experience with stripped sunshell was in 2000 blazer it made a low whine/grinding sound in the missing gear wouldn't have heard it with exhaust. It lost rev and I think 2nd & 4th I drove it 20 miles home in 3 as it would try for OD. I replaced it the same weekend with one out of 700r4 was going again for a couple years then traded it, its still going around town been about 4yrs. I would go for it but be prepared for the worst

 

[wheelman]

I'm looking at buying a '97 Yukon, which, according to the ad, slips in reverse. Guy told me the sungear is broken, but I didn't ask if he had somehow verified this or knew for sure. When I was looking at it, I put it in drive/reverse and rolled it a couple feet multiple times, each time it went into reverse without fault and made no strange noises. Truck was stone cold when I got there.
I plan to take the trans apart and try my hand at replacing any broken/worn parts. Would driving the truck about 80 miles home on the interstate with a broken sun shell or sun gear be destructive?
I'd imagine it most definitely would be if the sun gear is actually broken, because doesn't it usually take the reverse planet with it? Having the pulverized remains of the teeth of the planet and sun gear floating around in the fluid for that long would surely be awful for the rest of the trans, which is well worn anyway at 173k.
I didn't check the fluid when I was there, so I can't comment on what might be floating around in it. This issue really occur to me at the time because I had no idea what a sun gear was until I got home and googled it.

I'm looking at buying a '97 Yukon, which, according to the ad, slips in reverse. Guy told me the sungear is broken, but I didn't ask if he had somehow verified this or knew for sure. When I was looking at it, I put it in drive/reverse and rolled it a couple feet multiple times, each time it went into reverse without fault and made no strange noises. Truck was stone cold when I got there.
I plan to take the trans apart and try my hand at replacing any broken/worn parts. Would driving the truck about 80 miles home on the interstate with a broken sun shell or sun gear be destructive?
I'd imagine it most definitely would be if the sun gear is actually broken, because doesn't it usually take the reverse planet with it? Having the pulverized remains of the teeth of the planet and sun gear floating around in the fluid for that long would surely be awful for the rest of the trans, which is well worn anyway at 173k.
I didn't check the fluid when I was there, so I can't comment on what might be floating around in it. This issue really occur to me at the time because I had no idea what a sun gear was until I got home and googled it.
Thanks.

when my trans went-in my 1996 chevy van-i was a couple miles from home.drove it home missing a couple of gear.do not know about over drive-or reverse-i found that the chevy dealer-11 miles from me.had there own trans man.i called him.he pulled it out.replaced all the defective parts.that came in it from factory..chevy.people would never stand behind there products or make any of it good.to tear it apart and replace all weak and broken parts.850.00
i had them replace/install universal joints in the aluminum drive shaft.

do not for get to change.the two shift solenoids-while you have the pan off..and fluid out.do not buy factory defective parts.this trans man.bought parts.new and improved parts.for the trans from an out side source..that was like 5 years ago..

 

[honkon]

I bought the truck and it made it home fine. Transmission is in pretty bad shape. It isn't just missing reverse, second is also nonexistant and it never shifted into overdrive. Fluid looks dark pink-ish on the dipstick but is grayish black when rubbed on a rag. Doesn't really smell at all.
At first it wasn't making any strange noises, but after I got home I noticed there's a whining-like sound coming from it in park that definitely wasn't there before I set off for home. Reverse never really works beyond creeping a foot or two, and I can hear something spinning, a whirring sound, that slows down then stops a couple seconds after it is shifted out of reverse.
Can't the not shifting into OD problem be caused by the torque converter failing to lock up? I'm no expert, but I'm pretty sure it's not locking up. When you let off the gas in third the rpm falls to idle.
The shift interlock doesn't work, and can't that be caused by the brake switch, which would keep the torque converter from locking up? I dunno, the brake lights work.
EDIT-After doing some research, the sunshell is definitely stripped. I'm sure driving it 80 miles in that condition wasn't great for it either. Meh. We'll see.

 

[honkon]

Pulled the transmission out of this pig. Took a while but it was mostly painless.

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As you can see I broke the connector off the shift position sensor thingy. What must have been dialectric grease 20 years ago has since turned to glue. That thing was really stuck in there.
I'm waiting to tear it apart until my rebuild kit gets here, shouldn't be more than a few days.

 

[someotherguy]

Most likely the connector halves melted. You may want to look closer and give it a new range switch and possibly pigtails on the harness end.

Richard

 

[Black_cirrus]

Plan a new range switch, and that stuff in the connector sucks, but it's normal.