: How much can a 307 tow?

Night Wolf
07-15-07, 01:51 AM
Pondering here.... need a tow vehicle for a one time haul.... only thing I've got with a hitch is the Caddy.

Hitch is pretty big, the car was set up to tow our camper, 18'... maybe 2,500-3,000lbs?

Car has progressive rate springs in the back too... huge aux trans cooler.

I would be looking at around 4,000lbs, going slower, probably about 3 hours on somewhat flat terrain, but hilly in areas.

I dunno if the Caddy is up to it or not.... it is alot of weight, but that is kind of in the middle of what the chassis is capable of. What do ya'll think?

Jonas McFeely
07-15-07, 03:34 AM
A pile of dog feces maybe.

I just did a WICKED sweet burnout in the Brougham at the corner of Southcot and Triplet Lake Dr. just to see if she was up to it. So much smoke. It was nuts.

Less than 1 week...

The Ape Man
07-15-07, 06:47 AM
I used one of my 4000lb Cadillacs to tow another 4000lb Cadillac. Was an 1,100 mile run. Not pretty and I would not do it again. The tongue weight had to be pretty high to eliminate sway. The level ride wouldn't keep up with all the weight. Trailer sandshoe was more than a little thin at the finish. I used a U-haul trailer. 50 MPH tops due to uncontrollable sway at higher speeds. Very scary $#!t. We added some weight under the hood of the lead car (HD chains and jump box) and it actually helped things a bit.
Maybe delivery should be included in any pending exchanges. :stirpot:

07-15-07, 06:55 AM
When I was researching this for my wagon with the G66 heavy duty air leveling suspension, you CAN put a class III hitch on it, but you won't be able to tow more than 3,500 lbs.

In reality, I don't know how long your tranny would last without an auxilary tranny cooler.

This is why I want a LT-1 wagon, towing capacity is the same as a 1500 Suburban :thumbsup:

Night Wolf
07-15-07, 11:47 AM
Car has a big aux trans cooler, tranny was rebuilt a few years ago.

The car would only be towing for around 115 miles.

07-15-07, 04:10 PM
What really limits you is ability to monitor the temperature in the transmission. Rebuilt transmission and cooler and nice. It's the spikes that destroy the transmission. You need to be able to see this and make decisions on whether or not to act.

The chassis and suspension will be alright for it. At 4000lbs the tow rig must have brakes or you are endangering yourself and those around you. 4000lbs is either a lightweight tow rig or a lightweight Cadillac. I think a Cadillac Cimarron and a tow dolly is still pushing 3250lbs (~2600lb car, ~650lb tow dolly). What are you hauling, or is it a surprise?

I'd not be afraid to make the trip in 3rd gear. I'd definitely install a cheapo transmission temp gauge to complete the towing package you have put together. I'd also get the best assessment of the actual haul weight. Remember that the 7000lbs or other absurd rating you'll see for the later Fleetwoods ***does not*** take into account the frictional losses from aerodynamics and mechanical dynamics. People often overload their tow vehicles because they only consider static weight.

07-16-07, 01:22 PM
Colemen brings up a good point. My V4P Fleetwood CAN tow 7000 lbs. But that is assuming a 180 lb driver, and minimal stuff in the car. The key is not to exceed the Gross Combined Vehicle Weight (GCVW), that is the key weight. And do not exceed the tonque weight. My Fleetwood is rated 840 lbs tonque weight. That with the stock auto leveling system is about maxed. GM specifies that if the compressor keeps trying to run while you are towing to disable it and to add stiffer springs to properly support the rear end, or reduce tonque weight. I have 94-96 Wagon springs in now, they are around 10% stiffer than V4P rear springs. I highly recommend them for anyone who likes a more balanced car. My wife likes the ride, so it passes the important tests....

Trans temps, keep em down. Get the largest cooler you can find. All cars need one. I have a massive one in my 80 T/A, and only the factory one in my Fleetwood, which is decent. I would like larger though. A gauge is a good idea. Even a coolant temp gauge will work, but you will need to plumb in some sort of pipe fitting that it can fit into to make it work.

Do NOT use OD. Only the 4L80E is designed with OD towing in mind. Do NOT even TRY! I highly recommend fresh fluid before you tow. Synthetic is a good idea, and if you have higher miles, then replace a couple quarts with 10W30 or 30W synthetic. My stock 4T60 (not E) went 275K miles with it like that. And shifted great still.

Proper gearing and even the 307 can tow 5000 lbs (you probably would need 3.73's to 4.10's if you will do it often!). But won't be terribly fast at it, the 4.10's would be best choice if you want to be faster. Shoot for cruise rpms in the peak torque range, which is why you need the gearing, in addition to the gear multiplication. The Fleetwoods (RWD) all have sufficient brakes for 7000#. Remember, over 2000 lbs you should have trailer brakes anyway.

Prepare for it, expect a lot of heat, watch all your temps carefully (get a gauge package in, oil pressure, oil temp, coolant temp, and trans temps)

07-16-07, 01:25 PM
Oh, if you have 2.56 gears, for that weight I think I would avoid towing, that is gonna be torture on the trans.... 2000# is probably the max for 2.56's....

Night Wolf
07-16-07, 05:38 PM
Yeah... it dosn't look like I would be going that route anyway.... decided to pass.