2.73:1 Rear - Do I have a chance in hell to......

[grummy]

So, yes, I have the 2.73:1 Rear ratio, 305 and a 700r4. 65 mph in 3rd without the lockup turns under 2000rpm. Is there a chance I will be able to pull my 3000lb 6x12 converted Cargo Trailer, or should I already be seeking a better axle option ?

Seems I can find a used rear axle affordably, but I'm sitting here in Winter with the trailer stored and starting to think I'm probably not going to be happy once warm weather comes.

My only other tow option is a 2016 Chrysler Minivan, of which I have pulled the trailer a few times already. It does pretty well actually, with my worst mileage running at 14 mpg. I know the truck can't touch that, but I'd like to pull it with the truck if I can.

 

[jh86]

I think it’s more of a how well will it pull it question. Depending on your personality, send it jk

 

[AuroraGirl]

So, yes, I have the 2.73:1 Rear ratio, 305 and a 700r4. 65 mph in 3rd without the lockup turns under 2000rpm. Is there a chance I will be able to pull my 3000lb 6x12 converted Cargo Trailer, or should I already be seeking a better axle option ?

Seems I can find a used rear axle affordably, but I'm sitting here in Winter with the trailer stored and starting to think I'm probably not going to be happy once warm weather comes.

My only other tow option is a 2016 Chrysler Minivan, of which I have pulled the trailer a few times already. It does pretty well actually, with my worst mileage running at 14 mpg. I know the truck can't touch that, but I'd like to pull it with the truck if I can.

youre nto doing at the speed of that road. so if you can do it on 55mph roads, id say so. avoid hilly areas. youre not putting any torque in 4th gear so badly it may not adviseable to use it at all
The 305 being a 350 and a 2.73 being 3.08 would be a lot different lol

 

[jh86]

youre nto doing at the speed of that road. so if you can do it on 55mph roads, id say so. avoid hilly areas. youre not putting any torque in 4th gear so badly it may not adviseable to use it at all
The 305 being a 350 and a 2.73 being 3.08 would be a lot different lol

Don’t stop there, that 454 and 4.10 is just around the corner. Joking aside, for the effort of axle swap, 3.73 at least

 

[AuroraGirl]

Don’t stop there, that 454 and 4.10 is just around the corner. Joking aside, for the effort of axle swap, 3.73 at least

3.43 or whatever may be decent too,because its clearly an mpg build truck. the 305 is fine enough but the 2.73 is just ridiculous to use it for anything truck like. it literally should be the Suburban Mom(female) or Pavement Princess(male) package ratio.

 

[77Dmax]

Leave it out of OD. If it starts gear hunting between second and third, shift it into second until it'll maintain third..

 

[AuroraGirl]

Leave it out of OD. If it starts gear hunting between second and third, shift it into second until it'll maintain third..

careful on that, depending on the year 700r4 this may or may not allow the converter to lockup, which if it doesnt will toast the trans anyway, but the shifting may help it do that.

 

[SquareRoot]

Cummins and a 4l80 swap.

 

[Ricko1966]

Okay you have the trailer and the truck all you have to do is hook up and go for a test drive,which is exactly what I would do. We can arm chair quarterback this for weeks,what is acceptable to one isn't acceptable to another. That being said a 700r4 with a 2.73 rear gear is about the same 1st gear as a th350/th400 with a 3.55 rear gear, plenty of old 283 pickups with 3.55s and three on the trees pulled plenty of stuff heavier than 3000lbs. Stay out of O.D. and hold your shifts longer.

 

[AuroraGirl]

Okay you have the trailer and the truck all you have to do is hook up and go for a test drive,which is exactly what I would do. We can arm chair quarterback this for weeks,what us acceptable to one isn't acceptable to another. That being said a 700r4 with a 2.73 rear gear is about the same as a th350/th400 with a 3.55 rear gear, plenty of old 283 pickups with 3.55s and three on the trees pulled plenty of stuff heavier than 3000lbs. Stay out of O.D. and hold your shifts longer.

only because of first gear tho, for take off. which is a fair point, i forgot the first gear was optimized for 700r4

 

[Ricko1966]

only because of first gear tho, for take off. which is a fair point, i forgot the first gear was optimized for 700r4

You are right I meant to say 1st gear in a 700r4 2.73 is approximately the same as as Th350/Th400 3.55 .Getting it rolling is the hard part,now, if he holds his shift points a little longer before he goes into second, it still shouldn't be too far off. I think 700 has 1.63 second th350 1.48 second ,final drive in second 700 around 4.5 th350 about 5 25 2nd

 

[bucket]

careful on that, depending on the year 700r4 this may or may not allow the converter to lockup, which if it doesnt will toast the trans anyway, but the shifting may help it do that.

I disagree with this. Driving around in OD with the converter unlocked will toast the trans. Driving in lower gears (higher rpm, less load, less slipping in the converter) won't hurt it at all, just like a non lockup th350.

 

[AuroraGirl]

I disagree with this. Driving around in OD with the converter unlocked will toast the trans. Driving in lower gears (higher rpm, less load, less slipping in the converter) won't hurt it at all, just like a non lockup th350.

I did not word it properly. I was saying, that, driving in OD, with proper controls, your trans will lock up. even if it shifts a lot between 3 and 4. but depending on the year, im pretty sure there may not be lockup in 2. sustained driving would be bad if it wasnt able to lockup in that gear, esppecially with a load.


But you say it would be okay, I defer to you on this I was even gonna quote you since we mentioned in the past you know of some models where 2 has a lockup, maybe it was on cars?

 

[bucket]

I did not word it properly. I was saying, that, driving in OD, with proper controls, your trans will lock up. even if it shifts a lot between 3 and 4. but depending on the year, im pretty sure there may not be lockup in 2. sustained driving would be bad if it wasnt able to lockup in that gear, esppecially with a load.


But you say it would be okay, I defer to you on this I was even gonna quote you since we mentioned in the past you know of some models where 2 has a lockup, maybe it was on cars?

Lockup in 2nd and 3rd is for economy (or the hope of it) purposes only. Driving in 2nd or 3rd with the converter unlocked won't hurt the trans at all.

 

[grummy]

Lockup in 2nd and 3rd is for economy (or the hope of it) purposes only. Driving in 2nd or 3rd with the converter unlocked won't hurt the trans at all.

Well, I've seen people make that statement that if it doesn't lock, the trans will overheat... But I didn't really believe that... All trans prior to lockups didn't "overheat". But if this was because early 700r4's were questionable, well, I believe they were, but lack of lockup is not what burned them up. Glad at least the trans I put in it is from 1989.

I'd love to hook up and go, but the trailer is in storage and covered. Winter here.... I figured some guys already "lived this scenario" and would have a tale to tell.

I see a lot of people target 2800rpm as the optimum for towing with a 350/305. I think in Drive (3) with lockup, I'd be a little over 700 rpm under that. I suppose I should see where peak torque was on this 305. I got time for armchair quarterbacking right now!

Thanks for all the comments !