89 suburban for a tow rig

dware173

Active Member
Joined
Jan 17, 2006
Location
cave spring, ga
i just bought an 89 suburban with only 86,000 original miles on it and was wondering if it would make a good tow rig.it has a 350 with i believe a th350 tranny a 12 bolt rear limited slip with a 3.73 gear.i have been told i could tow my jeep with it and have seen people tow cars and what not with them so i was just want to get an idea from others about it. thanks drew
 
my dad has an 89 suburban 2500 4x4 with the 350 and turbo 400. He got it with about 20k on it and has pulled a 32 ft camper all over the southeast with it for most of its life. Hasnt ever gotten the best fuel mileage or had the most power but enough, and just now got its 1st engine and tranny rebuild at 210k....

I think there are a few that pull with them on here too...
 
Two different burbans, First mentioned is a half ton, the second a 3/4 ton. The first burban is marginal as a tow rig. I say this because it's a big, heavy truck by it's self, and the added weight of a trailer the braking power will be diminished, even with brakes on both axles of the trailer.

The second mentioned burban has larger front, and rear brakes so it can handle more weight towing.

A good up grade would be a 14 bolt and either front suspension from a 3/4 ton truck or burban. Pretty easy and for the most part would be bolt in.

The 1/2 ton burban with the 12 bolt also has c-clip axles, while the axle shafts themselves are slightly bigger than a Dana 44.
In stock form the 14 bolt has massive drums and brakes. beware, some 3/4 ton trucks and burbs come with semi floater 14 bolts. Smaller Ring and Pinion, and are also c-clip IIRC.

So yes, you could tow with it, but it's not ideal.

Another note. Run a tranny cooler. the Turbo 350 hates the heat of towing, but is a good tranny. The 400 is a heavier duty tranny and is built for more abuse, torque, and horse power.
 
dware173 said:
i believe a th350 tranny a 12 bolt rear limited slip with a 3.73 gear
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Did someone swap trans and axles? 1989 1/2-ton should have TH700R4 4-speed OD auto and 10-bolt rear axle.

Hook up your trailer to it and see how much the rear sags. You will at least need a weight distributing hitch, or else air-bags, or add more leafs to your stock pack. I added more leafs to my stock pack in my 1990 Burb - it used to sag in the rear with no trailer hooked to it.

I towed 7000 lb of TJ and trailer, and it did fine. 3.73 gear is good with stock size tires. Keep it out of overdrive when towing (if you do have a 700R4).

Drive conservatively, have good trailer brakes, and see how the braking works for you. You *must* have trailer brakes that work well. Upgrading to 3/4-ton axles and brakes like Upnover mentioned is not a bad idea - tow with it as-is and see if you think you need it.

Watch how much tongue weight you put on it, because as Upnover mentioned, you can overload the 10-bolt or 12-bolt rear if you don't pay attention.

I like the weight of the Suburban when towing. Since it's heavy, the trailer can't push it around.
 
I bought an 88 Suburban 1/2 ton with a 700R4 and tow package. I towed a fairly heavy car trailer and various second generation Firebirds and an GTOs. I normally towed in Drive, but if I was on the interstate towing on flat roads, I would go to OD. I believe it had 3.73 gears. I installed a tranny cooler on it as soon as I got it.

I bought it around 1990, so it was fairly new and had about 70K miles on it. I fried the tranny within 10K miles. I had the tranny rebuilt with a one year warranty, and fried that tranny in less than a year.

I sold that and bought a 78 GMC Suburban with a 454 and TH400 and 3.21 rear gear. It had 60K on it when I purchased it, and it went to over 200K before I had to rebuild the tranny.

Prior to that, I had a Chevy 1/2 ton truck and fried the TH350.

I recently parked my 78 GMC and I'm beginning to tow with my 96 Suburban with a 4L80E. It seems to be doing OK, but I'm in the market for a heavier duty truck.

You could probably tow a jeep with a tow bar using your Suburban, but I would not tow anything much heavier than about 4000 lbs, even with a tranny cooler. I don't think the 700R4 or TH350 is suitable for towing.

Mike
 
My 90 K5 has over 200k miles on it. The stock 700R4 was rebuilt by GM under warranty at 25k because it was shifting hard. Since then, all I've done is change the trans fluid and filter at recommended interval or whenever the fluid started to change color. I have put a lot of miles on it towing 5-6k pounds. I have never fried the trans. It does *not* have an external cooler on the trans, which is dumb - if I was still using it to tow I would add one, but it's only a wheeler now.

The previous owner of my 1990 Burb fried the original 700R4 at 88k miles. The Burb was a interior finisher's truck, and while not beaten on, weighed at least 6k itself and had at leasy 2k trailer hooked to it every day. They had GM rebuild the trans, said it cost $2500 (which is way too expensive, but is probably what the dealer charged them). I bought the Burb right at 100k miles. I immediately put an external trans cooler on it, I keep the fluid changed, and it now has 130k on it with no issues.

Bottom line - different people have different experience with the TH350 and 700R4, depending on the trans itself, how you drive, how it is maintained, and luck. Run a good cooler on yours, keep the fluid and filter clean (I have been running Redline synthetic ATF lately). Use it and see how it treats you. If you have trouble, either get a *reputable* rebuild, or go to TH400.
 
At the time I had my 88 Suburban, I was living in Charlotte NC and towing my trailer to WV on a fairly regular basis. I'm pretty sure the damage occurred while towing in the mountains, even while running in Drive.

You can also buy an in-line tranny filter with a temperature sender for your Suburban. It mounts under the hood, and uses a high performance oil filter. Filter changes are very easy.

I added that to my 78 Suburban and kept the temperature below 210.

Mike
 
so do yall think i could tow to and from ure from cary and not have alot of problems since it is really all flat road or should i just suck it up and drive my jeep there and work on the burb?
 
I would verify all the components you have (what trans and rear axle for sure?), add an external trans cooler, add a trailer brake controller, and try a short local tow.

Do NOT tow it without functioning trailer brakes - it's illegal and you're just asking for an accident.

See how it does. You won't know until you try.
 
could i get away with doing the tranny cooler and just keeping an eye on the tranny temp or should i really just replace the rear end and tranny when it goes.
 
WOW! I remember the days, back when I was racing dirt cars, that I would have been elated to have this nice of a tow vehicle! Best I ever had was a worn out '74 Crew Cab Chev with a 350, with a 400Th without a cooler.

Unless yer trailer is some kind of "heavy" equipment trailer, I wouldnt be a bit afraid of towing a Jeep around with a 'Burban in fair condition. Especially over flatland.

And as I would advise anyone towing anything...use yer head; slow down, remember the extra weight, and drive beyond yer hood ornament!

BTW...would be very suprised if it has a 350TH in it. Doesnt it have an OD? If so, just dont tow it in OD
 
i towed my jeep once with our 97 4wd 1500 suburban.... for 10 miles.... then i turned around and went to triangle to rent a 1 ton diesel.... it was horrible tryign to tow my jeep with it... if it had some suspension upgrades or perhaps a heavier load range set of tires maybe it would be better... but i can't see it being much better....
 
ol'Jeeps said:
WOW! I remember the days, back when I was racing dirt cars, that I would have been elated to have this nice of a tow vehicle! Best I ever had was a worn out '74 Crew Cab Chev with a 350, with a 400Th without a cooler.
Click to expand...

Your dirt car weighs less, and has a low center of gravity. BIG difference.
Besides, sounds like your tow rig was a 3/4 or 1-ton based off the TH400 comment.. ;)
 
dware173 said:
could i get away with doing the tranny cooler and just keeping an eye on the tranny temp or should i really just replace the rear end and tranny when it goes.
Click to expand...

Be prepared to at some point be broke down on the side of the road,...maybe. I towed for 6 years with a J-truck with a dana 44 rear. I had beefed up the rear springs, and I also had (have) a trailer with brakes on both axles. I also have a lot of experience with towing. I mention that because of you really have to adjust your driving style. Lots more room between you and others on the road. Allow a lot more room to slow down and stop, and never be in a hurry. Maintain your brakes and so on. Bearings tend to wear out quicker too. Yeah you can do that, but a 14 bolt is pretty much a bolt in replacement and a lot of insurance.
Rich said:
Your dirt car weighs less, and has a low center of gravity. BIG difference.
Besides, sounds like your tow rig was a 3/4 or 1-ton based off the TH400 comment.. ;)
Click to expand...

A lot of Chevy trucks and burbs come with the th400 Also remember the Chevy and the GMC versions differed slightly, the GMC version back in the day seem to be a little heavier built. And another note: back in the day, lots of folks ordered this or that on something they were buying new to get what they wanted. These days one dealer finds it at another dealer, and you have it a lot quicker.
 
2x on what Chip said

Rich said:
Your dirt car weighs less, and has a low center of gravity. BIG difference.
Besides, sounds like your tow rig was a 3/4 or 1-ton based off the TH400 comment.. ;)
Click to expand...

Yep 3/4 ton. (Oops...thought we had a 2500 Burb'n here! LOL!) Dirt car 'n two-row rack of tires, and my Jeep bout the same weight. Prob Similar COGs.

Reckon I'm not considering the "Jeep" in question may be a "rig", being much heavier than my mild built Jeep. I pull my Jeep, on a trailer, with a Durango with a tow package. I have to balance the load on the trailer. And, Im at the limit of its braking. (The Hemi will pull it much faster than the Brakes would stop it! But the speed is my responsibilty.) I probably wouldnt try to pull a full built rig with my setup.

The suspension rating shouldn't be as big a factor with a tag trailer, if it is loaded properly, balanced and minimizing the tongue weight. The 12 bolt is a good rear for the torque, but not weight loading. Biggest weakness I would see is the braking. Trailer brakes would go a long way. And if its a 350TH...that wont last if pullin a lot of hills.

This being said, I wouldn't drive this package across the country. Nor would it survive daily duty. I understand the limits of my towing package and try to operate it accordingly.
 
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