LOWTYD

I'm pulling a 5000 lb boat with my 2001.5, just bought it 3 weeks ago. Already installed 4 inch exhaust, and BHAF. My problem is that I have pulled this boat with my wifes 2005 4-Runner, and it seems to pull it with less drama. IE- Constant shifting, or hunting for gears. This is my 3rd diesel, my last on was an 03 H.O. six speed. I love the new truck, but I feel like I should be able to pull this boat in OD at 65mph with no problem. The 2001.5 just seems to be working to hard w/such a light load. By the way, the 2001.5 only has 60000 miles on it, and the trans is in excellent shape.

lsgibb

I would imagine that the tranny problems are due to the 315's you've got on there causing your gear ratio to be too small.

duner

you should be able to pull 5000# as fast as you dare.

TxDiesel007

get rid of the large tires

with that 3.55 rear u probly have those 315s have u to less than a 3.0 rear ratio.. NO GOOD for pulling (unless of coarse ur bombed) Nonetheless, get rid of the large tires, or solve ur issues with a set of gauges and a fuelin box...

best of luck..

Tx

BigBlue

Go have your speedo recalibrated. Mine shifted alot better after I had mine done.

LOWTYD

BigBlue, Thats kind of what i was wandering, about speedo calibration. I know the truck shifts at a certain speed, and because of the big tires, its lugging the motor. So should i go with something like a hypertech power programmer. I think it allows you to recalibrate for bigger tires. Thanks for any help.

firestorm

the Dealer can re-cal the speedo. There is a post on here, explaining how to do it. My dealer first told me " we can't do larger than 265's." After telling them how to do it, they did it and waived the shop fee.

600 Megawatts

The tires and gears are fine. Any boat that could be pulled with a Toyota four runner, you should be able to tow in OD at ludicrous speed. Your 315's only knock the ratio down to about 3.25 and you have a diesel for crying out loud, thats a perfect ratio.
There is something wrong for sure, and its not your gears or tire size.

KP

RAM2940

Well i think its a combination of the larger tires, gear ratio, and the auto tranny. I have a stock 2001 and i was pulling about 1500 lbs through danville and martinsville, va. the other day and it seemed like it did not want to climb the rolling hills unless i was going about 65 mph. Any slower and i would start losing alot of speed.

LOWTYD

ram2940, you know where im coming from. In the hills around here it really struglles. I've already learned not to use the cruise. I know it would pull fine if i cut off the OD, but when you run in the hills for a long time with OD off, the MPG drops to about 10 mpg, and i dont go by the overhead computer, I use a gps to figure my mileage. Anyone have any experience w/ the hypertech programmer, I think it adjusts for larger tires.

lsgibb

I have to disagree (no offense) but I think the 315's and 3.55 gears drops the rpm's too much at certain speeds. Even with the 6 speed there are speeds I find that when pulling a hill it seems like one gear is too high and the other is lugging, I can imagine that the auto would be worse. 65mph is one of those speeds, in my 6 speed that is about 1700 rpms which when empty is fine but when pulling 4k lbs it feels like it's lugging, but if you down shift to 5th then it seems like too high and you lose a ton of fuel. Now let's say you have 285's now the rpms are about 1900 at 65 which is right in the Cummins sweet spot of 1900-2100 rpms so it would pull that 4k lbs like nobody's business.
You gotta remember that with 315's you have to add 10% to whatever speed your doing to figure out how fast you are actually going so if you want to do 65 then the speedo should be on 59.

fabricator

I have a auto w/3;55 gears and 285 tires
at 60 MPH it is at 1600 on the tach
is good without a load, is bad with 7000# load
But if i get smaller tires I don't think that the tach
will raise a whole bunch ?
have gotton used to hitting the lockout button on the O/D
when it comes to a hill and it rocks on
and the EGT's seem to like this arrangement much better

deezel

there is a t.s.b on flashing the computer to remove limits on fuel delivery in overdrive that were put there to protect overdrive unit.

600 Megawatts

There you go, Mr. Deezel has found the problem.



KP

LOWTYD

Deezel, Thanks for the reply, how would i go about finding that t.s.b about the fuel in OD. Do i just get the dealer to do the reflash.