I just had a new ring and pinion installed with a TrueTrac Posi and new bearings and seals in my 01 Screw with 5.4L. I changed the gears because of tire height and lack of gitty up and go. My question is how much whine is exceptable in new gears. It doesn't whine all the time just between 35-45 mph and it is the loudest when I'm up to that speed and press the pedal just enough to maintain a constant speed. I had 4.10 Yukon gears installed with the Detroit TrueTrac posi. Just curious before I take it back and ask them to check it out. I've only had the truck back for two days with approx. 100 miles. Thanks for the response.

 

If the gears were set up properly, it shouldn't whine. Although you get what you pay for if you got a cheap gearset. 35-45 is exactly where a ring and pinion whine comes in. Ford's gearsets require approx 0.010" backlash to remain quiet.

 

mine does the same thing after installing the gears and tru-lok posi at that speed and i went with cheap gears. so what type of gears do you have. it may just be the gears.

 

Yukons are considered a cheap brand of gears?

 

hmm i thought they were good gears i have seen a lot of people use those gears without problems

 

Yukons are very good gears. I don't think everyone read your OP very good.

Ya it sounds like they are a little tight maybe.

But ya they arn't set up right.

 

i thought so

 

Thanks for the replies. I'm taking it back tomorrow to let them listen to it and hopefully fix it. I'll let you know the outcome. As far as the gears go, I always thought that Yukon was a good gear to go with. The shop that did the install uses their gears all the time and they build drag cars and race cars. Just hope it gets fixed. I absolutely love the power difference with the lower gears. Even with my 32" tires it seems to really want to get up and go. HUGE DIFFERENCE.

 

I have 4.10 Ford Racing Performance Parts gears, installed at a 4 Wheel Parts Performance Center. No issue what-so-ever. FRPP are on the cheap end of the price scale & 4 Wheel Parts is suppose to be a bunch of idiots. I'm not sure which gears are suppose to be "cheap". But Jegs has their own brand that is lower priced. And despite all the bashing, my local 4 Wheel Parts has competent techs & they do match & beat the lowest price you find.

 

Took it back to the shop and they did some adjusting and it still made the noise so I took it back to them. The owner told me the installation is spot on and that he is calling Yukon to see if they will swap out the gears for a new set to see if that fixes the whine. Should have an answer by tomorrow. As far as the Truetrac limited slip and the power difference, I absolutely love the change.