47Rh Issue, tranny guru's please help.

[ahale2772]

94 dodge, 47RH, 15K miles on a full rebuild (red clutches, most else stock)

TRE valvebody, and a DPC tripple disk.

I'm having an issue with the trans holding power, and I do not believe its because of slipping clutches. Trans fluid is crystal clear, not burnt, no tint to it indicating clutch material. In normal driving, shifter in D, if I give the truck anymore than 1/2 throttle, on the 1-2 shift, secondgear will instantly slip and disappear. If I come to a stop, 2nd comes back, then driving is normal, hits gear hard, shifts perfect. if I shift the truck from a stop (manual), it will hold power, so far Ive only tried up to 3/4 throttle but it seems to shift fine with no slip.

Also, I've been having a reoccurring issue where my trans is dropping out of 3rd gear manual lock. With lock up switch on, if I mash the throttle, it sometimes downshifts (locked) to second then back to third (violent). And today, at about 1700 rpm, i felt third gear locked slip (can see how its the brandy new triple disk slipping?)

Last but not least..... the metal shavings.

(the bare metal circle is just where I welded a drain on.)

right below the pickup of the filter in the pan, I have seen a scattering of shavings, they arn't really consistent, no large chunks, but lots of think slivers. I've got a large 10Mic external filter as well, so I'm confident nothing is getting back into the trans but WTF????

tested my line pressure, 95 psi at idle, 140 max in OD locked. I turned up the line pressure today, (two full turns) but none of my symptoms have gone away. With the way the trans is shifting when I go easy on it, I cant see how any bands or clutches are worn out. Bands looked to be adjusted well when I looked today. My gut tells me its a worn thrust washer or something.... but I've got little to no knowledge of the inside workings of these 47's so its anyones guess....

sorry for ranting.... help?

 

[Big Blue24]

What are the power mods or how much power do you think it's making?

My daily driver with stock turbo runs 140 psi max line pressure in overdrive and I wouldn't dare push it over 450 hp without more pressure. I've got a set of twins nearly ready to go in but I plan to adjust the pressure up to around 200 psi max in overdrive before I pump the horsepower up to the 550-600 range.

In my opinion, you need at least 185 psi in overdrive to hold 500 HP long term with stock clutch count. I don't think anyone builds a 47rh that will hold 500+HP 1000+ ft/lb long term with just 140 psi peak line pressure. If you still have stock clutch count, 140 psi in overdrive translates to about 125 psi in 1st-3rd gear. That's only 25-30% more pressure than stock so if you still have stock clutch counts, stock servo and lever ratio, your tranny is only good for 270-280 HP long term.


As far as 2nd gear, what ratio band lever are you using? Does it have an upgraded strut and anchor as well? Has the servo been upgraded or is it utilizing the stock servo? Are you using a flex band or a solid band? You ought to put a pressure gauge on the intermediate servo port and verify it's getting proper pressure when 2nd gear is acting up. It might be a valvebody problem not properly feeding the servo and therefore causing 2nd to come and go and slip at times.

 

[ahale2772]

Will, 480/960 is where its at for power, You had allready told me to bring the line pressure up. I originaly had a guage on the acc. Port, started with 120 psi max, went three turns and the pressure came up to 140, then went another 2.5 turns yesterday. id guess i'm at 150 or so, i'll throw a guage on it tonight.

What servo port will show a possible 2ndgear issue? And what should I look for? Drop/delay in pressure? I would not rule out a valvebody issue, this TRE VB has been nothing but issues.

Stock lever, servo, strut, anchor, upgraded flex band.

 

[YOUNG GUNS15]

Your on borrowed time with a stock lever and 150psi line pressure.

The reason it's slipping at only half throttle is there isn't a lot of line pressure built yet, Wire the tv lever wide open for a while and see if your trans will hold at half throttle. Also with the crazy locked downshift from third to second is defjnatley a sticky valve in the vb. I had the same issue and had to have mine gone through and cleaned up.

 

[Big Blue24]

Will, 480/960 is where its at for power, You had allready told me to bring the line pressure up. I originaly had a guage on the acc. Port, started with 120 psi max, went three turns and the pressure came up to 140, then went another 2.5 turns yesterday. id guess i'm at 150 or so, i'll throw a guage on it tonight.

What servo port will show a possible 2ndgear issue? And what should I look for? Drop/delay in pressure? I would not rule out a valvebody issue, this TRE VB has been nothing but issues.

Stock lever, servo, strut, anchor, upgraded flex band.

The stock strut is probably bent and causing the 2nd gear problems. Seems like they can bend once you hit about 120 psi line pressure. It's like $25 for an upgraded strut and you don't have to pull the tranny to install it.



Here's a picture of what it looks like:

 

[Big Blue24]

Will, 480/960 is where its at for power, You had allready told me to bring the line pressure up. I originaly had a guage on the acc. Port, started with 120 psi max, went three turns and the pressure came up to 140, then went another 2.5 turns yesterday. id guess i'm at 150 or so, i'll throw a guage on it tonight.

What servo port will show a possible 2ndgear issue? And what should I look for? Drop/delay in pressure? I would not rule out a valvebody issue, this TRE VB has been nothing but issues.

Stock lever, servo, strut, anchor, upgraded flex band.

The stock strut is probably bent and causing the 2nd gear problems. Seems like they can bend once you hit about 120 psi line pressure. It's like $25 for an upgraded strut and you don't have to pull the tranny to install it. Although it is under the edge of the valvebody so it probably has to be removed. I've never tried changing one out with the valvebody still in-place.



Here's a picture of what it looks like:

 

[Bponci]

Upgrade your anchor as well. They will split.

 

[Big Blue24]

Billet anchor picture, definitely need to remove the valvebody to install a billet anchor.

 

[ahale2772]

Will, thanks for the pics, I'll order those this week for extra assurance anyways. I bet you are correct on the strut being bent. I will drop the pan and take a look tonight.

 

[Big Blue24]

It is common to upgrade the lever, however, I don't know where they commonly break. I have seen pictures of broken levers but I don't think its a common occurrence. Usually the lever is upgraded to gain the bigger 4.2, 4.4, or 5.0 ratio in lieu of the stock 3.8 ratio. That said, if you're going through the hassle of pulling the whole tranny, you might as well buy a billet lever for $45 instead of cast lever for $25.

 

[ahale2772]

I Cant pull the pivot pin for the lever unless i can access the front of the trans hu?

Can the strut and anchor be done by just pulling the VB?

 

[Big Blue24]

I Cant pull the pivot pin for the lever unless i can access the front of the trans hu?

Can the strut and anchor be done by just pulling the VB?

Yes, tranny must be pulled to change the lever due to the pivot pin access point.

Yes, the strut and anchor can be changed when the valvebody is removed, no need to pull the whole tranny.