2008 F150 Trans and Transfer case rebuild questions
 

I recently picked up a 2008 F150 XLT 4x4 5.4L with 91,000 miles from a buddy of mine. While he was driving down the highway, the transmission extension housing (that connects the transfer case to the trans) apparently broke in half and caused the transfer case to shift back and fall off of the trans output shaft. The drive shaft slip yoke also had the holes elongated, probably from the severe angle of the transfer case after falling back. So it needs a new transmission, drive shaft and the transfer case needs to be gone through and checked for any damage. I decided to dig into everything myself (limited funds) and was looking for a little advice from some of you with experience.

For the transfer case, I'm planning on pulling it apart to check to make sure the shaft isn't bent. While I'm in there, I figured I might as well replace all of the bearings, bushings, chain and anything else that looks worn. I see a bunch of kits offered online, but no one ever says what brand of bearings or seals come in their kits. Who sells a good quality rebuild kit for this transfer case (BW4406)? Or should I just get the OEM parts from Ford? I don't mind spending a little more to be sure that I'm not using sub-par parts.

For the Transmission, I'm ordering a new case, it broke where the shaft exits. Due to obvious stresses put on the output shaft, I ordered a new. I also want to address some of the weak points of the trans, so I also ordered the Sonnax Forward drum, HD Sun gear and HD Stub shaft. Are there any other hard parts that would fix any other inherent problems? For the rebuild/overhaul kit, who puts together a good one? I've been looking at the Oregon Performance HP Master Overhaul Banner Box Set with the Torrington bearings and adding the full bushing kit. Is this a good quality, well put together kit?

For the Torque converter, I'm not sure exactly what stall speed I need. I emailed a few places asking about which one is correct for my truck but only one place answered back, Oregon Performance. They said the 1900-2000 stall speed matches my stock converter for my truck, but the OEM Ford service manuals I have say that the stall speeds should be:

4.2L = 1983 min 2334 max
4.6L = 2124 min 2488 max
5.4L = 2288 min 2734 max

When I emailed them back asking about the difference, I never received a response back from them so I'm still confused. What is the correct torque converter needed for my truck and who makes a quality one that wont break the bank?

Sorry for all the questions, but I would appreciate any input. I want to make sure I get everything back together correctly so I don't have any problems pop up down the road. Thanks.

I'm not looking for instruction on how to rebuild the trans or transfer case. There are plenty videos on the internet for that (at least for the trans). I'm just looking for some advice:

1. If anyone who works on these transmissions and transfer cases, and has seen the same type of failure, can tell me if there's anything in particular that I should replace for sure or what I should look for.
2. What Trans Rebuild/Overhaul kits come with quality parts? Is the Oregon Performance kit I linked to earlier a good kit for the money? Any other weak points in the trans I should address?
3. Any ideas about the correct stall speed for the torque converter? I keep finding conflicting information. Do the 2288 min - 2734 max stall speeds in the manual sound right or would it be beneficial to go with a lower or higher stall speed?

Thanks.

#1 - I would purchased a dyno tested transmission. Unless you got a lot of time on your hands to go through and measure all the parts, I'd just buy ones that are already done.
#2 - Not sure. For general use, stock is fine.
#3 - 2288 min - 2734 max stall speeds is correct.

Thanks ManualF150 for taking the time to respond, I appreciate it. I looked at the remanufactured transmissions, but didn't like the terms of the warranties. If something goes wrong they want it to be taken to a trans shop for diagnostics, which I understand. The problem is the warranties specifically say that they will only pay up to $300 for the shop services, even if the fault is theirs. Anything above that and I'm on the hook for it and there's no way any shop will remove, diagnose, fix and reinstall a transmission for $300. This was the same policy for almost every remanufacturer I looked at (not including the one's that wouldn't even honor the warranty if it was self installed). I have no desire to pay for other people's mistakes.

I have plenty of time to tear everything apart and the correct tools to check all required clearances, even for the correct length reverse servo. Besides, all remanufacturers and rebuilders only replace the bare minimum they have to. I'm going through the whole thing and upgrading the weak parts and replacing quite a few other parts to insure a longer lasting trans. At least that's the plan. LOL

I guess I'll just have to make sure whatever kit I go with has quality parts and it should be good.

Thanks for the verification of the stall speed. I thought the specs in the manual should be right, but I wasn't sure because of others telling me something different. Do you know of any descent priced, good quality torque converters?

I would go with OEM parts, including a torque converter.

Your repair manual should give you guides on the proper thicknesses of parts too. Hopefully.

I suggest getting a good caliper to measure parts. I invested in a Mitutoyo caliper a while back -- dead nuts accurate.

We have a member who can fix you up with quality rebuild parts, he could even sell you a properly built transmission. Contact him through his website, not through the forum.

http://bcatransmissions.com/

Thanks for the suggestion, but I haven't come across a Ford OEM transmission rebuild kit. Do you have a part number?

As for the torque converter, the Ford one is definitely the cheapest option @ $205 shipped. If I can't get a definitive answer to who's building quality converters that aren't going to bankrupt me, then I had already planned on getting the Ford one. I just figured an upgraded/beefed up converter from a good builder would add to the performance/longevity of the trans. The problem is that the reviews for a lot of the torque converter rebuilders are old, so I'm not sure if they're accurate of the quality that's being put out by them now.

The factory manual has all of the specs for the clearances and thicknesses of the different plates/rings where applicable. The section for disassembly and reassembly is pretty good. Combined with the Transmission Bench videos, they both provide some good, thorough instructions.

I agree, quality measuring instruments are a necessity. Luckily I already have both a Mitutoyo caliper and a depth gauge, along with two types of dial indicators. So I won't have to spend additional funds for them.

Good to know, thanks. I'll have to see what parts he has. I already have quite a few parts and specific tools in hand for the rebuild, so a complete trans is out of the question at this point.

Let him know what parts you already have and take his advice if he says any of them are no good. He builds solid Ford transmissions.

Yeah, Darrin seems to know what he's doing... he's also been on here for a while...

Thanks guys, I'll have to shoot him an email and see how well I did with my parts selection.

Let me know if you need anything.

D

I tried to respond a couple of times last week, but they both were held for moderator review and never posted to the thread. Hopefully this one goes through.

This is what I have so far for the rebuild. Everything is going into a brand new transmission housing.
*OPT HP Master overhaul kit
*Torrington bearing set
*Bushing set
*Sonnax HD Forward drum
*Sonnax HD Sun gear
*Sonnax HD Stub shaft
*Superior K092 super tough plate
*Superior K0132 center support snap ring
*Superior K0117 Billet 2-3 accumulator piston
*Superior K085 Billet overdrive super servo
*All new Ford electronics, both inside and out
*New Ford reverse servo, spring, cover and snap ring
*New Ford OD shaft, spring and snap ring
*New Ford snap ring and cover for 1-2 accumulator.
*New transmission output shaft
*Ford transmission pan with drain plug

Still trying to figure out if I want to use a Sonnax valve body repair kit or just order one that's already been gone through and rebuilt. Still also need a intermediate spiral retaining ring.

Darrin, are the HD 1-2 and 2-3 accumulator springs on your website good to use on a mostly stock set up like mine or just for use with the modified valve bodies you sell? Anything else you can think of?

Does anyone know the part number or where to find this screen for a 4R75E? The trans I'm parting out was a remanufactured one doesn't have it. Since I'm rebuilding the trans with a brand new case, I'd feel better using one to make sure if there are any small machining chips in the case, that they don't cause any problems.

https://cimg1.ibsrv.net/gimg/www.f15...eaa1af5b35.jpg
Image borrowed from the internet

Perfect. You're google-fu is definitely working better than mine today. Much appreciated.