Lift/speedo/warranty - Diesel Forum

steves67 · 04-29-2009, 09:03 AM

Just got a left over 2008 F250 XLT ext cab...
Needed it to pull my off road jeep around, and Got it for a good price...

Now with 2k miles on it..I'm finding the stock continental A/T's really stink in the dirt.. so I need tires...Since I'm there, maybe I should lift it 4.5" too , go with 18" chrome and 37" MTZ's.

Sooooo... will this set up hurt any towing or load capabilities for the truck?

How does the speedo get recalibrated ?

What about warranty? Will any of the proposed parts void my warranty?

This is a driver / tow rig, that will never be off-roaded ( on purpose )

Thanks in advance

SmokeyWren · 04-29-2009, 10:27 AM

Quote:

Originally Posted by steves67

Now with 2k miles on it..I'm finding the stock continental A/T's really stink in the dirt.. so I need tires...Since I'm there, maybe I should lift it 4.5" too , go with 18" chrome and 37" MTZ's.

Sooooo... will this set up hurt any towing or load capabilities for the truck?

Of course. Depending on which tires came on your truck, the taller tires will in effect change your final drive ratio to longer legs. So if you have 3.55 ratio with LT265/75R17 tires, then changing tires to BFGoodrich AllTerrain T/A KO 37x12.50R17D will give you an effective 3.17 ratio. That will kill your towing capability unless you change the ring gear and pinion in both axles to about a 4.10 ratio to give you close to stock performance, or a 4.30 ratio to give you better towing capability.

The weight capacity change will depend on the quality of your lift. High quality lifts are not cheap. Cheap lifts will reduce your weight-hauling capability.

Quote:

How does the speedo get recalibrated ?

With an expensive scanner or diag system that can access the ABS module in your truck. Your Ford dealer will charge you about one hour labor rate to do the deed. Or with a speedo calibrator you can buy for a street price of about $200, then DIY. The most popular calibrator is the SuperLift TruSpeed.
TruSpeed™ Speed Sensor Recalibrator · Superlift · www.superlift.com

Quote:

What about warranty? Will any of the proposed parts void my warranty?

Of course. Any mods that are don't meet Ford specs for your truck can void the warranty. The oversize tires can void the drivetrain warranty. The lift can void the warranty on the suspension any anything else the service manager decides might have gone south because of your mods.

Quote:

This is a driver / tow rig, that will never be off-roaded ( on purpose )

Then why ruin it with a lift? Go with the biggest tires and wheels that were available for your truck, then you won't have to worry about voiding the warranty. LT275/65R20 tires on 8x20 rims. Those tires are about the same diameter as the old 35s. Check out the Michelin LTX A/T 2 in that size.
Michelin LTX A/T 2
Also, Goodyear makes three different tread patterns in that size, including ATS, DuraTrac and MT/R.

And if you buy new rims, your best bet is to buy only "take offs" for Ford pickups. Or if you insist on something different, then be certain that the new rims are "hub centric" with a pilot bore of 125.22 mm (4.93 inches). Most aftermarket rims are lug centric with a pilot bore of more than 5 inches, and that is not only dangerous for you and yours, but will also void the warranty. Notice when you remove a stock wheel from the hub, the center hole fits tight around the hub. That's hub centric. Very few manufacturers make hub centric wheels for our trucks. One is Ultra. Check out their Predator 8.
http://www.ultrawheel.com/pdf/rims/286.pdf

You'll still need to calibrate the speedo for those 35s, but you probably won't need to change out the ring and pinion gears if you can live with a little less towing capability than stock.

steves67 · 04-29-2009, 02:20 PM

Awesome.. Exactly the info I was needing...Thank you. Alot of great info there.

Though, you have me second guessing / re thinking the lift...

It is a Rock Krawler...4 link front/ deaver rear....

The re-gear and/or warranty is the biggest concern, based on your post.

I have 3.73's LSD rear... moving to a larger tire will hurt... But will it hurt enough to worry about? I mean, at most, I'd be pulling a 10k , 24ft enclosed trailer around the southwest... moving from the 34's to 37's , with a diesel, going to make THAT much of a difference?

firemansdiesel · 04-30-2009, 05:28 PM

Get an Accu-Pro Calibrator from Pro comp ($199). It's also a code reader. I have it and works great for re-doing the speedo for bigger tires.

W/ 3.73 gears w/ 35" or 37" tires will drop your rpm's down at highway speeds and you will get a little better mileage, but stop and go will get you on the mileage. Towing w/ 35" tires you will not have a problem. With 37" tires you will feel sluggish off the line unless you get a tuner/programmer or change to 4.10 gears to get you going again.

Every dealer I guess can be different. When I approached my dealer at the shop level. The head shop guy (forgot the position title, but deals w/ warranty issues) told me that they would not void any driveline or components w/ a mild lift (I specifically asked him on a 4.5" suspension range w/ 17" wheels on either 35" or 37" tires). That stuff is on a dealer level and they have no problems replacing a ball joints, etc.... The only time he said I may or someone at my dealer could run into warranty problems w/ a lift. If someone has a aftermarket extended warranty. He usually says they can work around them to get it warrantied.

He was firm about touching the emissions components or extra power.

steves67 · 04-30-2009, 07:55 PM

Glad to here that, because I made the move today to move forward with the lift and tires...
Getting the 37" MTZ's for a smokin price, so I have to go that route. I hope the order to be placed for a set of 18" SPY's chrome...Also bought a access vanish tonneau cover today...

I if I ever had a warranty issue with the mild lift, I should be ok, too..

I'm not planning any tuning/programming ..other than the tire sizing ...

I'll deal with the gears too...I won't be touching them..unless I break a ring and pinion someday.
I have a little time before all this happens...the supplier is waiting for his tires from goodyear, before He sells me the MTZ's

I have a code reader.. If fact, a full mac mentor scanner.... should I just pay the 1 hour laber for the dealer to resize for the tires?

firemansdiesel · 04-30-2009, 10:21 PM

Quote:

Originally Posted by steves67

should I just pay the 1 hour laber for the dealer to resize for the tires?

If your going to stick w/ 37" tires and the dealer can program a tire that size, go for it.

If not then get a speedo programmer.

steves67 · 04-30-2009, 10:46 PM

I assume I can program others rides as well.....Might be a good tool to have in the tool box... I think I'll buy the prgrammer...looks like they can be bought for less than the $199... Dealer will be $120, I'd bet...

firemansdiesel · 05-01-2009, 12:28 AM

Yeah, I was quoted like $125...Was not worth it to me if I decide to jump up to 37" later on. Might as well pay $199 and save some coin.

**jimd1050** · 05-03-2009, 09:43 AM

Quote:

Originally Posted by steves67

I have a code reader.. If fact, a full mac mentor scanner.... should I just pay the 1 hour laber for the dealer to resize for the tires?

Just from experience 'cuz I just had it done, the largest tire available on the 2008 programming is +/- 35". There are three places in the software that it has to be changed - read the excerpt from another post of mine below.

Quote:

I just had my '08 done by the dealer and there were 3 places he had to change the size. The first module he went into under "Tires" had one setting for "PCM" and another for "ABS". He couldn't plug in a random number - only pick from a list. My 35's have a "revolutions per mile" of 598. The closest (and largest tire diameter) available was a "285/95R-18" which had a rpm of 596. We picked that for both "PCM" and "ABS" and saved it. He backed out and there was another module that said "Tires/Axle Ratio" - he went into that and everything was populated except the " tire rpm" - he again selected that odd tire and hit save. My speedometer/odometer is now correct as well as shifting points, braking, etc. I don't know if the software is the same for earlier models but that's the procedure for '08 - '09 trucks.

Hope this helps...

steves67 · 05-03-2009, 09:25 PM

Yes, That helps...

So I have to buy the accu pro to calibrate for 37's...

tly · 05-03-2009, 10:52 PM

SmokeyWren:

Are all 2008 Ford wheels "hub centric"?

I've got a 2007 DRW, and I know it is hub centric, but your comment makes me wonder if the newer SRW rigs went hub centric too, or are they are still lug centric?

If the SRW rigs are hub centric, what year did Ford go to the hub centric system on SRW rigs?

Thanks.

dt75flh · 05-04-2009, 12:32 AM

in my case I tow a large toyhauler (39' and my rock krawler fits inside)and couldnt lift the truck due to the fifth wheel....

the stock 20" tire measures around 34" tall.....if a fifth wheel is ever in your future take it into consideration

I went with a 2" spacer and put airbags on the rear for when I am towing....I also put a larger 20" tire that is a 35.5 x 13.50 wide....I also went and put 4.10 gears in....My speedo is back to only being 1 mph off (gps verified) which is basically stock..

If anyone is thinking of changing gears....spend the money on FACTORY ford gears in the rear...you can use aftermarket in the front.....the new trucks are so quiet inside that with the aftermarket gears you can hear them whine
( the aftermarket gears are slightly smaller to fit both the sterling 10 1/4 and the 10 1/2 ....they make up the difference with the bearings hence the whine)

SmokeyWren · 05-04-2009, 08:29 AM

Quote:

Originally Posted by tly

Are all 2008 Ford wheels "hub centric"?

I don't know about all Fords, but all Ford Superduty pickups have hub-centric wheels and hubs.

Quote:

I've got a 2007 DRW, and I know it is hub centric, but your comment makes me wonder if the newer SRW rigs went hub centric too, or are they are still lug centric?

All Ford SuperDuty pickups have hub-centric wheels and hubs.

Quote:

If the SRW rigs are hub centric, what year did Ford go to the hub centric system on SRW rigs?

When the SuperDuty first came out as a '99 model in 1998.

steves67 · 05-04-2009, 10:30 AM

I have no plans for a 5th wheel... My enclosed trailer is on 24ft... and I think that is big enough for my needs...I think..
I am planning to hold onto everything to go back to stock, if need be... Just in case...

In regards to hub centric... The spy wheels are listed as NOT being hub centric, but does includes adapters when needed...

However, Smokey, you say stock hubs are 125.22 MM... While the SPY wheels show they are 125.50 mm...
That seems very close to me, and should be hub centric?
Or at least be good enough?

steves67 · 07-03-2009, 07:08 PM

Finally got the truck lifted, yesterday..Still tweaking

As Planned..RK 4 link, deaver, 37's, 18" monsters...

I went to the dealer today to have the speedo calibrated.. No go... They don't have a selection, to program, anything close to 37's.... So a aftermarket re-calibrator seems to be in order...

Here is the only pic I snapped, because we finished about 8pm last night..