Sorry for no update I've been out of town on business, just ordered the book should have it tomorrow. Still waiting on a few other parts, but hoping to have a chance to build it this coming weekend.
A904 Woes.. not working right..
- Thread starter MonkeyMadness
- Start date
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Question for yea all. 4.2 vs. 5.0 vs 3.2 or 3.8 lever? Geez.
I've read soo much and heard pro's n con's for all. Ordered a 5.0 from summit and will have it tomorrow, but now I'm 2nd guessing myself.
Now I got a aftermarket rebuild kit with shift kit.
Opted for the "Heavy Duty" setup with the shift kit.
Little back story on the use of this trans.
It's behind a 318/396 stroker low ccr 9.5'ish :1
Mild cam. With fitech, Built for torque. In my 72 D100 with a 3:23 gear set out back . The truck is just a daily and for looks. Not hauling/ towing or racing.
What lever should I use with my combo??
I've read soo much and heard pro's n con's for all. Ordered a 5.0 from summit and will have it tomorrow, but now I'm 2nd guessing myself.
Now I got a aftermarket rebuild kit with shift kit.
Opted for the "Heavy Duty" setup with the shift kit.
Little back story on the use of this trans.
It's behind a 318/396 stroker low ccr 9.5'ish :1
Mild cam. With fitech, Built for torque. In my 72 D100 with a 3:23 gear set out back . The truck is just a daily and for looks. Not hauling/ towing or racing.
What lever should I use with my combo??
65TerrorCuda
Well-Known Member
I've got the 5.0 lever and no issue in 20 years. No idea if it requires matching adjustments or mods
If you don't have one, you should invest in a GOOD transmission cooler. The picture of the parts above shows burn marks so that guy was running very hot! Others who've used that 5.0 can chime in on the # of turns.
Did You find a cause for the damaged support? Once it became damaged, there wouldn't have been enough of a seal to provide the pressures needed by the clutch, if there was enough line pressure/flow to begin with.
Killer6,
Not sure which damaged support you referring too? I'm asking which lever ratio I should use that will fit my specific need for this build.
I'm pretty sure I'm the reason the trans is smoked, and the clutches damaged due to heavy footed MORON driving and trying to chirp the wheels while in (D) instead of (1)
MopaR&D
Nerd Member
Killer6,
Not sure which damaged support you referring too? I'm asking which lever ratio I should use that will fit my specific need for this build.
I'm pretty sure I'm the reason the trans is smoked, and the clutches damaged due to heavy footed MORON driving and trying to chirp the wheels while in (D) instead of (1)
I don't think that was necessarily why it failed, maybe it would have held together in (1) but after seeing your engine specs and the heavy vehicle it's in you're putting quite a bit of power through that thing. IMO no way a stock 904 without at least a shift kit would have held up to that for very long. I've stomped on the gas from a stop in my Duster with a ~450 HP 360 and the shifter in (D) quite a few times and it's held up fine but it has a modified VB (now with a proper shift kit as of a couple weeks ago) and some upgraded internals.
Hydraulic pressure holding the clutches together is crucial on these smaller automatics... 727s withstand a lot more without needing pressures bumped up because they have clutch packs with physically more surface area (larger diameter and oftentimes more of them in a pack). I second a good-size transmission cooler too, based on your location you can probably just bypass the cooler in the bottom of the radiator.
Regarding the lever ratio I'll check my TF book by Tom Hand when I get home, I know he says in there what is required for running certain ones.
Whether the sprag alone(which appears intact/didn't get rolled) held, or if the low/rev band held the drum, it would have -0- bearing on smoking the clutch. The higher ratio lever only increases the clamping force on the band, it has nothing to do with clutch apply whatsoever.Killer6,
Not sure which damaged support you referring too? I'm asking which lever ratio I should use that will fit my specific need for this build.
I'm pretty sure I'm the reason the trans is smoked, and the clutches damaged due to heavy footed MORON driving and trying to chirp the wheels while in (D) instead of (1)
And the kickdown/2nd gear band lever You are picturing won't do anything whatsoever in 1st/manual low, & the most common reason THAT band gets smoked is shifting @RPM from manual low, because the L/R band can't release fast enough before the KD/2nd band tries to grab the front drum. Even with an improved lever ratio, any overlap is won by the band that already has a grip on a motionless drum, that's the L/R band, so the kickdown band is always the loser.
The torn up alum. part is the "support", and if there's a lack of lube or improper assy./repair, it will be damaged, seals leak, pieces of debri clog fluid ports/passages, etc. The lever does -0- to address the damage I see, nor does it explain it.
Aww, Okay I understand your what you meant in your first post now... Yes the Support and the sprag gear were replaced. Why the damage I'm not sure but my plan was to replace anything questionable. As for the clutches and line pressure when installing the new shift kit I opted for the "heavy duty" option (larger holes in separating plate, a few new holes in valve body and a few new springs) for a bit more line pressure and firmer shift points. I also opted for the lvl 2 Alto clutches, with a 1.35" kick down band.
- Now with that all done my question was which lever ratio should I use with my current transmission build? There are a few options and I would like to only have to do it once.. Yes I understand this question has no bearing on the smoked clutches or the damage to the support housing, but as I'm in the trans repairing and modifying for my need it is relevant to my build...
65TerrorCuda
Well-Known Member
I'm sure you'll get your question answered here but meanwhile,
There's a guy named Richard that does youtube videos for precision transmission, you could try hitting them up. That guy takes apart a transmission and explains every part in one breath.
He does talk about lever options for chrysler trannies but I don't remember if it's in the above video
There's a guy named Richard that does youtube videos for precision transmission, you could try hitting them up. That guy takes apart a transmission and explains every part in one breath.
He does talk about lever options for chrysler trannies but I don't remember if it's in the above video
The 5:1 will clamp tighter, but will need a different adj., and as A body said...I'm not sure about combo of the flex-style band, that ratio, and the required adjustment..above My experience w/them...
And a HEMI Swap!.... but its just my daily and I plan the leave it as is, so I'll beef up the transmission I have now... boring I know
Not at all. Now he knows what it looks like!
The 5.0 kickdown needs the Hemi width band to go with it, or it makes no difference. Get the rigid wide band and you're good.
Here it is on the WIT Transmission site. It's the first one on the left. 1.750 width rigid band.
Whatever It Takes Transmission Parts $37.85 with a $5 core charge.
Whatever It Takes Transmission Parts $37.85 with a $5 core charge.
Thank you... I had found a thread mentioning this. Everything I'm reading talks about overlap time or setting up the shifting I've also noticed most manual shift VB are running the 5.0 and I'm not setting mine up for manual shift.. Think I'm going to stick with the stock 3.2 lever, I just need a good smooth trans that can daily.
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<smh>
MopaR&D
Nerd Member
That channel is great, learned a TON from watching his videos. He doesn't mention the lever ratios in that video but towards the end around 35:00 he talks about using proper servo springs to make sure the bands don't come on accidentally due to cross leaks, then around 36:00 talks about blocking the inside of the low/reverse servo "apart" for the quickest possible low/reverse band release on a manual 1-2 shift.
In Appendix C of the Tom Hand book there are "recipes" for high-performance TF builds, all of the ones for 904s recommend the 3.8 or 4.2 ratio. I'm not going to say more as I'm starting to go down a rabbit hole here and I'm not an expert lol. Does your shift kit mention blocking the accumulator piston or changing any of the servo springs?
Something to consider about the band lever ratio, it not only controls how quickly the kickdown band is applied, but it also controls how quickly it is released. So when the transmission is shifted from 2nd to 3rd, the band has to release while the high gear clutch pack is being applied. These happen almost simultaneously. The higher the ratio, the faster it is applied, and the longer it takes to release. High gear clutch clearance and number of springs in the high gear drum all are a factor when you change the lever ratio. If you did nothing else but change to a 5.0 lever, you may be very surprised with how your shift characteristics change. Being that you are sticking with a fairly stock rebuild, I would personally leave the stock lever. If you ever went to a reverse manual valve body where the line pressure is raised, then not only would I be ditching the flex band for a solid band, but I would be changing the lever ratio to 3.8 or 4.2 and increasing the number of springs in the high gear drum. Just my 2 cents. I have not read Tom Hand's book, but I am sure it explains it in there.
Install day has come. I was able to get it in and everything looks good. I'll pick up some trans fluid tomorrow morning. Test drive tomorrow.
I bought a deeper pan and have a trans cooler in route. I'll report back how it goes.
I bought a deeper pan and have a trans cooler in route. I'll report back how it goes.
Looks nice. I bet it will turn out fine. What fluid did you decide on?
Other than a shorter prop-shaft and a large slip-yoke?
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