Problem Changing the Gears Watch Out!!!
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From: North Florida
Problem Changing the Gears Watch Out!!!
OK, I have a 2008 F-350 FX4 Diesel with the limited slip 3.73 gear ratio. For those of you that are going to change your gears....watch out! For some strange reason, FORD has changed the 10.5 Ring, Pinion, and inner pinion bearing. If you are changing ratios, (I was changing to 4.10) the only way I have found to fix it is to use a 10.25" aftermarket ring and pinion with the factory shim and add an additional 120 thousandths worth of shim on the inner pinion bearing. This will work. Set your backlash like you normally would. Be careful, because as of yet you cannot replace the '08 Factory 10.5" with an older 10.5" set of gears, they do not line up. If you are having trouble try this. If you have any questions please contact me. I did not personally do this work, but I did have to find the fix because my installer was stumped. I ended up calling Drivetrain Specialists in Michigan and spoke with the Service Manager, Rob who had apparently worked on at least 40 '08 Trucks direct for Ford, and this was his fix. So, I tried it and it worked.
Banksstroker
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I Would Like To Involved With Fords Engineering People There Have Got To Be A Lot Of People That Would Prefer 4.10 Gears In These Trucks And Then They Would Sell Like Hot Cakes. Ihve Owned And Operated Ford F Series For More Than Forty Years And Ive Always Felt That They Were Geared To Fast To Be Full Strength. Ive Changed The Gears In Several Of The Trucks And Always Gained In Power And Fuel Econemy. They Are Always Trying To Fool With Government Listings To Get Epa Points.
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From: Oregon
The stock 3.73 gears are great for all around mileage and towing. If your only going to tow then the 4.10's would be great. I changed my 03 from 3.73 to 4.10 and lost 2 MPG. It towed great but it also towed well before. I will leave this one alone as it is the best of both worlds.
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From: North Florida
If you check the tire size to gear ratio charts, 35" tires normally show a 4.11- 4.56 ratio. When I checked, it appeared to be about 20 RPM off of the factory spec with factory tires/ ratios. This is why I chose 4.11. I also upgraded from a clutch driven limited slip to a superior gear driven limited slip front and rear. Why did I not go factory parts? Because I could not get availability or pricing, and heard rumors of R&P being $950 compared to $225 aftermarket.
Banksstroker
Banksstroker
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From: North Florida
OK, here is the most recent info. Tony from Reider Racing (a great contact) just called me after receiving my factory Ring and Pinion from my truck. With all of the problems that I was having we determined (over the phone) that the R & P and the inner pinion bearing had been changed on '08 trucks. Turns out after he measured my gears and compared them to other 10.5 R & P's that they are identical. The only difference according to him Tony is that the Inner Pinion Bearing is 120 thousandths longer on the new trucks. So, a 10.25 or a 10.5 replacement gear set should bolt up with 120k of shim. If you have any questions, call Tony at Reider Racing, he is the most knowledgeable drivetrain technician/ salesperson that I have ever spoken with.
Banksstroker
Banksstroker
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