|02-27-2013 10:39 AM|
I did install a new OEM servo pin today and I must say that this appears to have made the transmission perfect. It has very little travel. At the bottom of the range 0.075 inches. Thats tight but it is in spec and runs great. I want to thank you for the help in spite of my not being a hotrodder. This place is top notch!
I am thinking about upgrading the servo to a corvette. Im told that it is a good idea for my towing needs as well as for longevity. I do have a wide band in it. Is that thinking right?
|02-25-2013 09:25 AM|
Thanks fo rthe help. Jim
|02-24-2013 09:24 AM|
You need the hard DTC cleared so the system does not try to compensate for it. Some codes affect the system more than other codes
Most basic code readers can clear codes. Even Harbor Freight scanners can do that.
If you have the servo pin length all jacked up = incorrect, that can cause 2-3 shift timing problems. So can incorrect clearance setting in the 3-4 clutch pack
|02-24-2013 08:49 AM|
|02-24-2013 08:46 AM|
I did clear the code when I reconnected the battery. Drove the car for some time just now and I am getting the somewhat soft sloppy shift sometimes. I once got a flare in the 3-4 shift but only once. When I say flare I mean the RPM goes up like it istemporarily not in gear and then catches the next gear. Like the band and the 3-4 clutch pack apply are not properly synchronized. Could this be as simple as the solenoid pin travel is too loose. I have read that the tighter the travel the more firm the shift becomes.
Can this sloppy soft shifting harm the 3-4 clutch pack? Any thoughts?
|02-24-2013 08:34 AM|
|Crosley||If the CEL is on, you have hard codes set. Need to scan or try local budget auto parts place may have a basic code reader for use|
|02-24-2013 07:41 AM|
|fishcrazy||I tried disconnecting the battery leads for a while yesterday but the CEL stayed on. I left them disconnected overnight and will see if that worked. It did not seem to turn on when I started test driving the truck until I had been through several drive cycles.|
|02-24-2013 06:54 AM|
|02-24-2013 06:40 AM|
|fishcrazy||After installing the new pressure plate the transmission seems to shift normal EXCEPT for the one time it flared from the 2-3 shift. Only did it one time but it has done that before on a couple occasions. If I am not mistaken it was after I ground off the pin. At any rate it seems to be shifting ok now except for the one time issue mentioned. I will test driv eit again today to see if it remains good. It has not reset the CEL which is on. Do I need to disconnect the battery to reset that or do I have to have the codes reas to reset it or will the vehicle reset it eventually since the problem was fixed?|
|02-21-2013 09:45 AM|
|fishcrazy||I appreciate the input. I started with the pin grinding thinking that the band was too tight causing my problem that were actually coming from the pressure switch. So I guess I am thinking maybe I should think about correcting the pin grinding I should not have been doing. The pin travel was very close to the lower end of the specification length if not just under and I thought that maybe the wide band upgrade and the new reverse drum maybe caused the pin to be on the tight side. But now I am a bit concerned that it is on the loose side. I anxious to see how it shifts with the new switch installed.|
|02-21-2013 09:30 AM|
|rick 427||Talking on a standard rebuild,I personally have never ground on a servo pin.As long as the band had some wiggle on the drum before installing the pump,which it allways did,I shipped it. If it lasted 100k before the rebuild with the pin at that length,it'll go another 100k after a rebuild.Then again,I might add,all my kits come from an OEM supplier. As far as a corvette servo,all transmissions act differently with that servo installed,some shift nicer,some too firm for its application.And remember,this is a heavy escalade your talking about.You don't want that thing shifting like a hot rod,or you'll be replacing broken bands on a regular basis....just my opinion.|
|02-21-2013 08:39 AM|
I am planning to replace the manifold pressure swithc today and am hoping that this solves all my shifting issues. I have noticed some change in the shifting ( I THINK) since I ground off the tip of the servo pin some. I think that it is within spec but right at the longer length of travel spec. The shift seems to be happening with a slight amount of slip and a somewhat harder engagement than I previously had. If I continue to get this type of shift after replacing the pressure switch I am considering resizing the pen length with a extender that I put on the end of the existing pin or by replacing the pin with a new one. Is one preferred over the other? I read some post on here that said they had seen more than one of these extenders come off.
A concern is what effect does the pin being right at the higher end of the travel specification or maybe just higher than that have on shift and can it cause premature band failure? Also will a corvet servo be a good upgrade to the longevity of the transmission and just how much harder will the corvet servo shift be? Any advice from more experienced builders would be appreciated here.
|02-19-2013 07:05 PM|
If the PCM receives poor or no signal from the pressure manifold, that can set off the PCM into a default mode
|02-18-2013 09:04 AM|
|fishcrazy||I took the truck to a tranny shop and he put it on some kind of scanner and said I had a code for the defective manifold pressure switch which he said was in the transmission and could cause my symptoms. Im thinking this is the pressure switch assembly that bolts to the valve body tells the computer what gear it is in. do know that when I was replacing the o'rings on the face of the switch I inadvertantly removed the plastic film with one of the o'rings and just put it back on with the new o'ring. Could this be my problem?|
|02-16-2013 11:26 AM|
Thanks for the reply. The rebuild used a kit of the following:
Raybestos Blue Plate frictions in forward and overrun
Raybestos GPZ105 frictions in 3-4 clutch
High static OEM frictions
The Raybestos Pro Series wide band
Complete steel kit with turbulator reverse steels and kolene 3-4 steels
Complete gasket and seal kit
ACDelco 3-4 Apply and Backing plates for proper 3-4 clearance
Sonnax replacement load release springs
ACDelco 3rd accumulator check valve
I also put in a new reverse input drum and a used pump which I needed due to the stator shaft being unusable in the old pump and the bearings being badly damaged in the reverse drum. I also replaced the sun dome with the beast. The 1-2 and 3-4 accumulator pistons were replaced. A new OEM bonded separator plate was used. I replaced the 3-4 clutch piston and foward clutch housing and piston with new bonded rubber pistons. I did pull the pump apart and replaced the soft parts and filter but deemed the rest ok and reused.
I did not totally rebuild the VB but did replace the Orings on some that I had to remove. The forward accumulator seal was replaced. The 3-2-control solenoid and TC clutch solenoid Orings were replaced.
The reason that I rebuilt the transmission was that I lost reverse. All the forward gears were working properly when I tore it down and that is why I thought the electronics were good and I found mechanical cause for the lost reverse.
This transmission runs perfect for 5 minits or so. Then it decides it likes 2nd gear and only wants to be in that gear . I can still get 1st and reverse also.
I have beat my head against the wall trying to figure out what mechanically could cause this type of behavior to just start happening after the thing runs perfect for 5 or more minutes. I thought since the band had gone to a wide onethat the pin may be too tight and I did adjust the travel of that to be within specification. Only other thing I can think of isreplace the shift solenoids but they must be working properly for some period of time till it starts loving second and you wouldnt think that they would reset if defective.
I am going to have someone do the proper scan to check the computer is telling the transmission to do what it should be telling it to do. I just cant imagine it running perfectly and suddenly having just 2nd , no down or upshift.
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