Need help curing a problem towing 5er!!

[GOTSOOT]

Can any one offer any suggestions on how to cure my bucking bronco 12 valve pulling my 5er? the problem lies in the truck bucking or bouncing when the fuel is applied to accelerate, between about 1300 to 1700 rpm give or take a little,and usually only,repeat only in third gear. did gov. springs,over and over and over ,put a new set in,still no change. drives fine empty. Has anyone had any thing like this happen to them? I am wodering if the trailer has anything to do with this?using standard 5th whl. hitch,no gooseneck. Help,planning a vacation trip this coming Sun.

 

[Mark31]

Soot, I know this sounds way out in left field somewhere, but there is a reason I'm mentioning this. (Long, long story!) If your truck is a long bed with a center support bearing, check it out. Very unlikely this is the problem, but just check it out for laughs. Hope you find your gremlin! Mark

 

[Newt]

On Ford trucks, air bags solve the problem.

Newt

 

[Nyoest]

I have the same thing with my 96 after the dd south bend install. A lot of weight and a firm clutch results in a unwelcome buck taking off from a stop light. Air bags would help but the I think the real problem is loaded driveline angle and axlewrap. My solution until I can get air bags / ladder bars installed is to be more aggressive with the throttle and slip the clutch a wee bit more than typical. If has worked well for me so far.

Just reread your post,is the rpm flutuating or the chasis bouncing?

 

[GOTSOOT]

bronco riding 12 valve

crawled under and found the carrier bearing "Shot". Will know tomorrow, after bearing install. !Oo.

 

[GOTSOOT]

bronco riding 12 valve

new brging installed--better,but not cured!!

 

[Mark31]

Soot, now you can get down to the fun stuff---shimming to change the driveshaft angle, air bags, or, if all else fails, a 1 piece shaft if it is available for your year model. Maybe some one with experience here can chime in and help you. I think there is a thread about this, too. Hope you have a great vacation! Mark

 

[Grizzly]

I had a Furd gasser that buck on reverse while backing the 5er. Turned out to be a warped clutch caused by overheating the clutch when stuck in sand. Replaced the clutch, problem solved.

 

[Dick R]

I had the same problem with my 98 5 speed their was an up date for towing on these trucks it was a different set of springs on the side of the pump what they did was to apply more spring preasure to the linkage so a person does not activate the fueling on these trucks as fast makeing them surge , I don't have the part number anymore but it may be found in a search they did cure the problem and one spring can be removed for regulare driveing .

 

[khalsey]

I don't remember the tsb number but I had it done on my 1996 for the same reason under warranty when it had about 16000 miles on it. They changed out the throttle control rod assembly. (the # on the invoice of the throttle control rod is 14043005) The new one takes more pedal movement for the same throttle response. I still have the truck and use it to pull a heavy fifth wheel and it has never bucked since the rod was changed

 

[mwilson]

To add to what Dick R posted above... .



When the Freightliner FL series used the 12 valve Cummins they also had dual throttle springs. If one broke it did the same thing as your pick-up. Made the throttle too touchy.



Just a thought... ... .



Mike.

 

[DWeaver]

I have the same thing with my 96 after the dd south bend install. A lot of weight and a firm clutch results in a unwelcome buck taking off from a stop light. Air bags would help but the I think the real problem is loaded driveline angle and axlewrap. My solution until I can get air bags / ladder bars installed is to be more aggressive with the throttle and slip the clutch a wee bit more than typical. If has worked well for me so far.



Just reread your post,is the rpm flutuating or the chasis bouncing?

Brought home my (new to me) goose neck yesterday. Had the "surging" problem when trying to keep constant speed up hill. Sometimes it would surge and sometimes not. The rpm's would stay constant. The only time the chassis truly bounced was when I would try and power through the surge.



I would like ask if you think this is axlewrap? I have the one piece driveline. New u-joints. 2 piece throttle return spring.



Million dollar question, do I need to invest in airbags?