7.3 Weak points? What Tranhy mods for towing are MANDATORY?

[jonwright]

I'm examining purchasing an '03 250 7.3L with 36k miles on it. I"m going to be towing roughly 8k lbs and MAYBE 10k at the max.

I understand the 6.0L engine is stronger than the 7.3L. I'm gathering that the tranny on the 7.3L is the weak link here.

With my use of the vehicle should I go ahead and plan on rebuilding the tranny? What mods on the tranny would prevent early failure?

I understand changing fluid and a tranny temp guage help. What else?

I live in Arkansas and while it is kinda hilly it's not like we're in the mountains - most of the hills are only a couple hundred feet.

 

[Ford_Forgotton]

Take a trip to lead hill arkansas, and let Brian at BTS remove and replace your tranny. Best 3800 bucks you can spend on that truck. GARAUNTEED not to break, and will tow a house off its foundation.

I personally think the 7.3 is a more reliable motor, but the 6.0 does make some serious power.

 

[Tail_Gunner]

I'll second the trip to BTS.

I think the $3,800 figure is based on a "Your old tranny is a paperweight" assumption.

If it is still running good, I think the job is less because he is making upgrades and not repairs.

As far as a the 7.3 being a weak link, far from it. The 7.3 production run in the Powerstroke configuration was longer than the 6.0 production run which is supposed to ending before too long in favor of the 6.4. The early 6.0's were a warranty nightmare for Ford, costing them huge amounts of money for warranty repairs. The later 6.0's supposedly had the bugs worked out and are decent motors. Some folks over at TDS reported that the some of the last 7.3's made were getting more money on trade and used retail than the early 6.0's were. That doesn't sound like a weak link to me.

 

[hheynow]

Although I have a '97 with the E4OD and am not familiar with the 4R100, IMO the weakest link is the stock torque converter. Upgrading it will beef it up. BTS, as stated above, is clearly the tranny of choice ($$$$$$$). I lost my tranny yesterday and am having it rebuilt locally (NOT by BTS) with the heaviest duty TQ available for the E4OD. With the additions of the beefy TQ, a TransGo shift kit, pump mod, upgraded planetary and Redline ATF, I'm out the door for $2,600 tax included.

 

[CHPMustang]

Welcome aboard there Jon

If your wallet/budget doesn't allow for a BTS at this time then I and others highly recommend the Sonnax Kit ($50 plus fluid/filter) for the 7.3L's 4R100 transmission as the results are immediate and takes no time to install

Just about every truck that attends our get togethers wants the Sonnax installed.

 

[true91799]

I had an impromptu conversation with a gentleman who works in the Super Duty plant for Ford. He was driving an 02 like mine and told me "That transmission will last you forever IF you are willing to change the fluid every 10k miles."

The 7.3 beats the 6.0 hands down. Local dealers ALL chant the same thing. One mechanic said the 7.3 was using about 60% of its potential whereas the 6.0 was Maxed Out!

Just what I have heard through the "blueberry" line.

 

[NEokcTERROR]

BTS uses Precision Torque Converters www.converter.com

 

[jonwright]

Thanks, guys. I also have an RV with the V10 ('99 chassis) and I don't recall which tranny it has, but it will slip in OD if the fluid is old. So I keep fresh fluid in there.

I appreciate the help. Looks like first thing I'll do is change the fluid and keep it fresh.

I didn't think the engine itself was the weak point, but I was wondering what part of the drive train is, Tail Gunner.

Although I might look for a bit moor oomph, I don't want to drop a lot of money in mods and breaking/fixing stuff.

 

[NEokcTERROR]

Thanks, guys. I also have an RV with the V10 ('99 chassis) and I don't recall which tranny it has, but it will slip in OD if the fluid is old. So I keep fresh fluid in there.

I appreciate the help. Looks like first thing I'll do is change the fluid and keep it fresh.

I didn't think the engine itself was the weak point, but I was wondering what part of the drive train is, Tail Gunner.

Although I might look for a bit moor oomph, I don't want to drop a lot of money in mods and breaking/fixing stuff.

Your slipping is probably due to a damaged accumulator/accumulator housing these are external parts inside the pan and you do not have to remove the trans to replace them. What happens is the fluid pressure leaks past the seal in the accunulator, or the gouges in the accumulator housing. More than likely your filter gets partially restricted causing the pump to not be able to pull enough fluid through it to support the volume requirement of an internal leak, and thereby you lose line pressure at lower RPMs causing your slipping problem. While you are there if you do the sonnax kit you can probably save yourself a considerable amount of money in the long run. Eventually this problem will burn-up your transmission.

 

[SprintRacer26]

Your slipping is probably due to a damaged accumulator/accumulator housing these are external parts inside the pan and you do not have to remove the trans to replace them. What happens is the fluid pressure leaks past the seal in the accunulator, or the gouges in the accumulator housing. More than likely your filter gets partially restricted causing the pump to not be able to pull enough fluid through it to support the volume requirement of an internal leak, and thereby you lose line pressure at lower RPMs causing your slipping problem. While you are there if you do the sonnax kit you can probably save yourself a considerable amount of money in the long run. Eventually this problem will burn-up your transmission.

So would it be recommended to replace the accumulater/accumulator housing along with the sonnax kit and an atf change?

Whats the accumulator and housing cost?