I did some searching, but couldn't find anything definitive for my particular inquiry.

I had the trans in my (now defunct) '99 rebuilt and a shift kit installed about 6-1/2 years and 50K miles ago, and just picked up an '03 with 160K on it. Both are 5.4,s both are 4WD. While I've noted nothing amiss with the '03, given the mileage, I'm thinking of swapping the transmissions. (I'd want to put the '03's trans back into the '99, as I'm considering selling it "as-is, needs motor.")

Possible? More work than it's worth?

Additional considerations:

1) I don't know the cause or circumstances, but the '99 trans has occasionally (probably not more than 3 or 4 times that I can recall since the rebuild) jerked/banged a bit hard when shifting. It seemed to happen after deceleration, then accelerating again. Not repeatable, and not alarming, but a consideration nonetheless.

2) If I don't do the swap, I will at least want to look into a shift kit for the '03, as I don't think a truck should shift like a mid-80's Cadillac.

Thanks in advance,

Andy

 

Ford redesigned the valve body and changed how fluid flows through the transmission in 2001. The 99 transmission will work in the 2003 truck, but may not be as efficient

 

Thanks for the info.

Well, to avoid future mis-match issues, and since the '03 trans seems OK, maybe I should just leave them where they are. If that sounds like the more prudent plan, can you recommend a shift kit for the new one (or would you, given the mileage)? Can the J-mod be done to the '03 instead, and again, should it? I really don't like the slow/soft stock shifts, but am not looking for tire-burning transitions, either. I'd just really like it to shift "like a truck should."

Thanks,

Andy

 

Jmod all the way. I dont recommend removing any of the accumulator springs though

 

That sounds like a plan. Thanks!

In that vein, I've seen all sorts of "suggested" or "I did this" hole sizes, these usually being year-dependent and performance-related. (I also noted some lists on your Facebook page. Nice write-ups, by the way!) As I mentioned, I'll be looking for quicker/firmer shifts, but not neck-snapping performance. The truck will be a daily-driver, and may see some tow duty occasionally. I'd also like a bit quicker engagement from park to reverse and park to drive. If you'd care to advise your recommendations, I'd be grateful.

Thanks,

Andy

 

For your 2003 truck, replace the pressure regulator valve, boost valve and OD servo regulator valve with Sonnax replacement valves.

replace the factory separator plate with the Superior TUFF plate and drill the holes like this;

hole 1 = .160" #20 bit
hole 2 = .104" #37 bit
hole 3 = .180" #15bit
hole 4&5 = .113" #33 bit
hole 6 = .160" #20 bit
hole 7 = .093"
hole 8 no used
hole 9&11 = .125"
hole 10 = .093"

make sure to enlarge the holes for hole 4&5 in the gasket. I use a hollow punch for this.

 

btw...

 

Thanks for the added info. Very helpful!

Andy

 

I love the Superior plate, but am not a fan of the Sonnax valves due to way too many issues.

I don't like to cause problems with replacement parts.

D

 

Please explain. I have been installing Sonnax valves in every valve body I build for the past 3 yrs and have had ZERO problems

 

I think you have to keep in mind the sheer volume of these that I have done as well as how I test them. This experience has taught me that the quality control on those parts is lacking. I have had too many either stick during testing or leak. Also, I have had sharp edges on those ridges actually act like a cutting tool in the bore on the valve body and ruin the casting after just a short time of use.

I can't risk that. I respect those who get their products from me too much to send them anything that I have any doubt about. And, I have worked way too hard to build a reputation to toss it over poor choices.

As with a lot of these products, there are some really good ideas there. Trouble is with the implementation and the fact that they try to have them made as cheaply as possible. Take for example that ridiculous billet forward drum. Great idea. Awesome idea. The final product is a total waste of metal. Cheap Chinese metal at that.

With darn few exceptions, the best products are still the factory parts because nobody has been able to do it better on this transmission yet. Sure, there are some issues. If there weren't issues then none of us who do this would have a job. But when you find an issue you throw it out and replace it with a good factory Ford part. Don't create problems where there aren't any.

D

 

just so we are clear, I am only using the drop in replacement Sonnax valves. I Do NOT use the repair or oversize valves that require machining or boring.

 

I am talking about supposed stock size replacements. Very specifically what should be drop in replacements. The ones that aren't supposed to, but sometimes actually do their own boring as they are in use.

I think the reason for the others is because the first ones often eat their way into the need for them.

Just use good stock stuff. It's light years better. Ford isn't stupid and they have far greater knowledge and resources than anyone else making parts for these. They did address some earlier issues that created this idea that there is still a problem. Yes, you will get some wear on the stock pieces. But have you ever measured it? If there is wear then you check the bore and the spool. If the bore is good you grab a good factory spool and replace it. If not then it's all trash. This is why you buy valve body cores in bulk. Keep some, scrap some and save the good parts. It's what you do when you want to provide the best for your clients.

It also gives you a heck of a lot of stuff to play with and an inventory to customize with.

Don't fall for the internet and marketing hype like everyone else. This is why some products fail and others just don't.

D