towing performance

[SRehberg]

I just returned from our first time out with a 27ft. 5th wheel, and was really surprised to the amount of drag it put on hill climbing ability. I have a '96 CTD with the stock auto, no performance mods to the engine, and hitting the hills the thing acts like it has a anchor tied to its tail. The 5er weights around 5800lbs dry, and we had it really light, as it was just a trial overnight run. One hill I was in 1st gear, as it was losing speed in second! The hill was steeper than normal; a back roads two lane hill. A 6% grade and it's time to start downshifting; i. e. 3rd without lockup even. I can imagine the heat I'm making. The torque converter is pretty loose (stock) but locks up etc. Is this pretty normal for a truck that is rated to pull 10,400lbs?



Thanks for any input.



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'96 2wd auto, bone stock, pulling a 27ft. Alpenlite :--)

 

[Gary - K7GLD]

Somethin's WRONG!



I pull a 7000+ lb 5er - and even when my '91 was STOCK, could pull ANY Sierra grade at 55mph or better, in top gear! With listed mods, I can now top ANY available grade at 65mph and better - limited entirely by my better judgement and fear of tickets!



You might want to check/replace your fuel filter - a nearly clogged one will still seem to operate OK empty out in the flats - but will sure lose you lots of power in steep grades and pulling situations where higher fuel flow is needed...



Good luck!

 

[D. Showan]

Also check your converter, your 96 probably has one. If it's still there, take it off it may be pluging up.

 

[baby.driver]

Come On Gary...

That go for sonora pass also?????



Jay

 

[Joseph Donnelly]

I'm not too surprised. More power will help, and then you can afford to use a tighter torque converter too. With stock power, hill towing will be lame, and the stock converter helps your engine get to enough rpm that it makes the full 178 hp at the wheels.

Contact me off line if you wish, as power enhancements and fixes have been hashed a lot in the past--lets save bandwidth here.

 

[Gary - K7GLD]

JAY - I haven't tried Sonora pass - and suspect narrow, winding road MIGHT slow me down a little...



But I *have* regularly pulled up over 50, 80, I-5 into Oregon, and 101 in N. Cal into Oregon, the Grapevine in S. Cal, and over the Tehachapies (sp?), The Coast range between San Jose into Santa Cruz - to name a few... Many long 7% grades in that mix - passed MANY rigs similar to mine and NEVER passed by one of THEM!

 

[FParisi]

SRehberg -- Are sure about the wt of that trailer? I have a 32' Alfa that weighs 12,300 lb loaded to travel. If you have any slide outs its probably more than you stated.

If it hasn't been done already make sure you don't have the plastic quick disconnects on the transmission lines!

Get gauges so you know what's happening!

I'm looking to do the DTT upgrade and DD power upgrade to about 275 HP to make towing my brick ____ house to Montana more pleasant. Anyone with experience with these mods I'd like to hear about it - IT IS a lot of $$$.

Frank

 

[SRehberg]

I want to thank everyone for all the help, as it was really discouraging having it get weak like that. The cat is still on it, but it may be short lived if it is causing some loss. The fuel filter is overdue for a change, I have the new one, but the location makes it such a bit-- that I have been dragging my feet to change it. No more excuses now. The weight of the trailer is only what I read on the label, it hasn't hit the scales for offical weight, and the label matches the brochure, but that could mean anything I guess. The torque converter lets the engine wind up to around 2000rpm and when it shifts, there is very little rpm drop. When the TC locks up, major rpm drop, but it pulls harder at the lower rpm. I think the first thing to do is weigh the trailer, lose the CAT and then do some upgrades. I've been relucant to do HP upgrades due to fusible link known as the transmission. Anyone know the torque the 47RE is good for in a stock configuration?



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'96 2wd auto pulling a 27' Alpenlite N6KZU

 

[GLASMITHS]

SRehburg

I just replace or rather had my 47re rebuilt and updated+++++



However when it was stock, 75K worth, I never had a problem with it. Many times I tow 26KCGW of 5er and truck. Just don't push it. If it starts lugging downshift. If you don't have a transmission gauge get one. Good insurance. With your weight, you ought to blow over the mountains There is something wrong

 

[Deezul1]

I would suggest hooking up a fuel pressure gauge and checking for at least 18+ lbs pressure. I had a terrible power loss problem and it was the overflow valve which is a cheap and easy fix but needed a gauge to tell that it was at about 7lbs which power wise was fine empty and couldnt hardly get over 60mph towing a 6000lb travel trailer. With the combo listed in the sig I now can go as fast as I want up anything thats paved without bad curves, gotta keep an eye on the gauges though.

 

[LFarrar]

I vote fuel filter

I have seen same thing before on my dads truck and he has stick fuel filter is also cheep to try first any ways. I two week ends ago took grape vine in 6th at 65 mph with 30 ft 5er combined wt is 22000 lbs and 12 ft tall trailer,of corse was on 5% drugs stock clutch still !!!

 

[WyoJim]

SRehberg... If you are shifting through the gears at 2000 rpm's your are attacking hills like an old lady.



If you must drive like that lock it out of overdrive and the TC will lock up in 3rd. Keep your RPM's up around 2500 and it should be able to climb a tree.

 

[FParisi]

WyoJim - My 95 defuels at 2400 rpm -I drive the same way cause that works best with my configuration now, until I get the GSK + transmission upgrades. When towing I do have it in 3rd until 55-60mph before shifting to OD to keep the rpm up.

SRehberg - I didn't have a way to check the fuel pressure so I just ordered an overflow valve from Piers -preventive maintainance and pretty easy to change.

Frank

 

[SRehberg]

I plan on changing the fuel filter this week (work gets in the way of my playtime) and also would like to check the fuel pressure, but where do you tie the guage into? Is there a port that you can put the guage onto? I have read a about the overflow valve, but didn't pay real close attention, as it only happens to someone else... . right? Sounds like this 12 valve of mine has problems though. About the highest I have had the engine is around 2300 rpm, unloaded. Loaded with the trailer, it will only do about 2000rpm pulling, I guess that's the stall speed or close to it, of the TC. I appreciate all the help that you have offered, and will definetly go after it. I just purchased the trans temp guage and the turbo boost guage, now to save up a few more pennies for the EGT and pillar mount!



Does the fuel pressure stay around 18# throughout the rpm range?

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'96 2wd auto trying to pull a 5th wheel uphill

 

[Deezul1]

There is a bleeder screw in the top of the fuel filter and TST has a adapter that replaces the screw which is a good place to tap into the fuel system for a gauge. The other way is to remove a banjo bolt on the pressure side of the fuel system and drill and tap it for 1/8NPT and then go from there. If done that way you will need a snubber to dampen the pump impulses as it will kill the gauge. Automotive inline type fuel filter will work for a snubber, put it in the rubber line between the pump and the gauge. The minimum pressure should be 15lbs and is supposed to be around 23 or so. It should not vary much from that figure whether slow speed or full throttle.