[rockertype]

Has anyone used one of these (4TSB)? I was getting ready to purchase a 4L80E but just recently heard of this Ford based trans from FB Performance. It's a 3 speed auto with a transbrake & an electric overdrive. They claim it has been used in 3500 lb cars with over 1000 HP with no problems. It also has interchangable bellhousings to fit different motors. Almost sounds too good to be true! Any comparisons to a 4L80E? Is the 4STB just as good?

[TTS]

That's a Ford AOD with an Ultrabell. It's not a bad transmission when built up with 4R70W parts, hrdnd intermediate shaft and some decent frictions. A lot lighter than an 80 and nowhere near as strong, more comparable to a built 4L60 in strength.

[rockertype]

FB Performance's HP claims as well as the 4STB's gear ratios are similar to the 4L80 transmission. Overall cost of either tranny is about the same when you figure in the converter, crossmember, driveshaft, ect. What caught my attention is that the 4STB has an electrically operated OD. Unlike a 4L80 which must be manually shifted in & out of OD. That would mean more shifter choices (3 spd vs. 4 spd) when using the 4STB. It also can also be ordered with a traditional Pontiac bellhousing pattern. No need for a transmission adapter like the 4L80. The 4STB is supposed to be a bit lighter too.

For me it all comes down to durability. The 4L80 is a tough tranny to beat! I'd like to hear some input/info from someone that has actually used the 4STB. Not just claims from it's manufacturer.

[Half-Inch Stud]

I've been in hot-pursuit of thic combo. Took the 4R70W out of my spare Lincoln, tore it down, analyzed it. Findings:

1. All Frictions & Steels are Borg-Warner (some packs have smooth, some packs have grooved), all had excellent wear patterns and are fit for re-use EXCEPT; the Intermediate Clutch Frictions (4 discs) had wore teeth (I've seen this on only a few TH400 Intermediate Frictions (3 discs.)

2. 2-3 3-2 Accumulator had a broken Spring due to unconstrained plunger motions. Seems a mechanical-stop such as a simple dowel or a stop sleeve will make a design improvement.

3. Reverse-Apply is a band that is substantially similar to the TH400 LO-Reverse Band.
4. Engine-Braking band is "3x stronger" than TH400.
5. Overall, the"Hard Parts" are not impressive like T400 stuff. Here's why:
5A: FWD, Direct, and other clutch pack Drums are rather small diameter (~4.5") & made of corrogated Stamped steel. The stamped steel might be fine.
5B: Planetary gearset shows biggers gear diameters than TH400 but so what; the teeth are smaller cross-section, higher pitch for quietness, and is a 3-planet rather than 4-planet format.
5C: Input shaft not pressed-in fully for spline mating to FWD drum. Input shaft extension is tiny, has rounded splines, and appears to be a "fusible-link". If the Input shaft extensiont were to break under load, then you'd probably be able to drive home in some sort of gear.
6. Overall, the Case is impressive once the Bell-housing is whacked-off. Sems Easier to understand than a TH400. (I'm not fully understanding the 4R70W yet though, due to lack of time into this forray).
7. Front Pump & Tail shaft are impressive.
8. Stock TQ Converter is 13" and quite long. Adaptive Bell Housing WILL have problems with fitting the Converter into the PMD engine flange. Bell spacers appear to be needed: Perhaps a scatter plate (or stack of scatter plates) from a stick housing. I plan to use the stock converter (mine is the Factory's latest design) because the Hi-Po Converter prices are waaay top-shelf and may not feature the lock-up ability.

9. Bonus: 8.8 Rear Input Yoke appears superior to GM's U-joint straps.

The HIS summary thus far: The 4R70W is an incremental evolution of the AOD, cheap & easy to find, and appears to be suitable for Street, yet remains illusive to "see" how it can survive Slicks & >550FT-Lbs TQ.

The >900 HP claims are more than just 1 vehicle, with (from what I understand to be) stock hard-parts. Me thinks the 4R70W is in the PowerGlide weiht-limit zone; can survive in light cars. Likely to BUST the extension shaft, the input shaft or ClutchPack splines in a 3800Lb car with PMD power.

Seems that if the 4R70W was to grenade it will probably not puncture the case, probably not contaminate the Converter, so a fella could bring a spare 4R70W puppy to the track and actually swap-out the dead/scattered unit if it comes to that. The fella would be "out about $100 at most for each grenade, So, "Hey, more core parts." HIS

[Half-Inch Stud]

Oh yea, if I were tripping over 4L80's or 4R100Ws then duh, I'd be on it.

[BruceWilkie]

You need to investigate the availability/cost of improved hard parts. Things like 6 pinion planets hardened shafts etc.. For example a c4 is pretty weak as built but using aod parts and aftermarket parts can be built to handle 1000 hp. Cost to performance/reliability needs to be considered.

When I started my 528 Ford project I started doing research as to which 3 spd auto would be the strongest cost effective trans for my application. A t400 with a JW bell is hands down the winner. Not just my opinion but opinion of other s far more in the know than I.

I may be trading some parasitic losses but reliability IMO far outweighs any losses I might incur.(especially at the +800 hp level I'll be at)

If I desired overdrive and no loss of reliability I'd look no further than a t400 with a Gear Vendors OD(can be used to make your 3 speed a 6 speed as well). If your racing a JW bell isnt a bad thing for safety and strength or making use of a case core that has a damaged bell or Chevy pattern.

[Half-Inch Stud]

BruceWilkie; Good point. Yea, Gear-Vendor's OD Tail-Kit, along with Driveshaft shortening is Top-Shelf on Rel & Costs, and remain grenade-proof. Whereas the 4STB bought off-the-shelf is easily >2K and corrupts a fella's TQ converter & shifter, and by MY view may grenade in a heavy car.

MY Post is all about getting to Street/Strip OD for about the cost of the Bell-Housing. Using the stock 4R70W TQ, homemade shift control, and hopes for a moot Driveshaft swap, since there are plenty of driveshafts that might fall into place. Also, showing the cost of grenading can be bounded.

When a fella take a PGlide, TH350, 700R4, 200R4, or 4R70W and stuffs custom hard-parts to make it grenade-proof, then that is all the same to me as boring expense BECAUSE I like to repeat the one-off masterpieces inexpensively.

When a fella takes a TH400, or 4L80E and does frictions/steels/seals with some know-how, and the result is grenade-proof, then THAT's interesting to me. Oh sure there are hard-parts for these too. Now that's interresting for everyone.
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HMMM: just maybe the 4L80E's are a plenty due to Cash-for-Clunkers !!!
Uhm, oh yea, I checked. Not even 1 4L80E, but about 20 4R70Ws showed up.

[tininjun67]

""Unlike a 4L80 which must be manually shifted in & out of OD"
the 4l80 does not have to be shifted manually. It is run by a controller of your choice, which is programmable as to when you want gear changes to occur, including od. In order to engage the electronic trans brake, however, it must be manually shifted into
1st gear. (this option available with some shift kits) I shift my 4l80 into drive, then operate it with a series of switches. It looks like a hand held electric version of a lenco. No computer required.
I've personally watched a slightly modified (no new hard parts) 4l80e live behind an 830hp motor in a 4200lb car during drag racing, road courses, auto crossing and long trips without issue.