5R55E internal question

[greg s]

I am working on rebuilding my transmission and am in the process of inspecting all the parts before I order anything. I was looking at the overdrive drum assembly and have a few questions. The star washer adapter plate on the sun gear is chewed up as well as the drum where it engages. It looks like it tried to "climb" out and has worn the corners off the parts. Any ideas as what would cause it? Also what should the tolerance be for the drum fitting onto the pump bearing support? When I push on the drum from side to side, I can feel and see some movement. Typically I would think that it should be a zero tolerance part, but mine probably has .002-.003 clearance. The support and bearing looks good with no signs of splitting or damage. I could not find any specification for these parts. It seems that the overdrive drum takes a lot of abuse on these transmissions.

 

[SonicBlue302]

Hi. Not sure if this pertains to your rebuild but i was wondering if that drum is bad on my tranny, would it cause the o/d not to engage on my truck and rough shifting from 1-2 on an 01' Ranger with a 5r55e? Thanks.

 

[greg s]

Can anyone tell me if there where any internal improvements made to the internals of the 5R55E after 1997? I know I am going to need a new overdrive drum and I found some one that sells all the internal parts (good used) from the pump to the reverse drum in one set. So if a later year would be better and still work with my case, I could do that.

 

[partsman48210]

What year is your truck greg? The only thing I have found besides a straight rebuild is the superior shift correction kit. Its more about making things work better along with last longer by replacing a few parts and doing a couple modifications to existing parts. I'm going through mine right now which is a 2002 model

 

[greg s]

My Explorer is a 1997 and has around 250,000 miles on it. So its got some wear on the internals.

 

[JK080]

You want to stick with parts like what came out, changing parts out between the years can be more trouble than its worth.

Definitely change the OD drum and get a new star washer that fits into the lugs. Its a common wear spot, especially with those miles, I see it all the time, even seen them strip completely and destroy everything in there. I welded the washer onto the drum once when I was in a pinch and I never saw it again, but I would just get a drum if I were you.

The side to side clearance you have with the drum to pump hub, would be normal, it needs that clearance in there so the drum can ride on a layer of fluid on the bushing.

 

[greg s]

Thanks JK080 for the reply. I saw some where about the od drum lugs being improved on later models. As for the clearance on the drum bearing, is that the amount it would have when new? I am just concerned about excessive pressure loss.

 

[JK080]

Yes there are some changes in this area in the later designs, I just tend to stay away from interchanging parts, it can create some hard to fix problems. Your original one went 250k so it can last.

The drum clearance is only filled with lube oil from the lube circuit the apply oil enters the drum between the sealing rings, the rings will expand and seal to the drum creating tight seal. Obviously you can have too much clearance here due to a worn bushing but what ends up happening is the sealing ring groove itself on the pump starts to hit the drum and this will damage the drum and cause the sealing rings to fail. If the surface of the bushing and pump hub look good chances are its good.

 

[greg s]

Thanks again JK080. Are there any other specific areas I should be looking at for this high mileage 5R55E? The problem I had before I stopped driving it was a delay in fwd and reverse, everything else functioned normally. I probably drove it for a month like this, then one day a heard a slight rattling noise and checked the oil. It had turned dark, so I stopped driving it. There was no metal parts in the trans, but when I drained the TC I found a few tiny pieces. Also when I rolled the TC around on the bench I could here something loose/not normal. So it looks like the TC was heading south quick, but I don't know if that could cause the delay. The valve body was replaced a year ago with a CVB and the gaskets where in good shape when I disassembled it. Overall the condition looks good, and no big problem has been spotted other than the TC and the o/d drum notches.

 

[JK080]

Pay close attention to the pump and pump gears, with metal coming out of the converter it has to go through the pump, so look for wear on the gears and in the pump where they ride. Also the sun gear shell wears at the lugs that meet the direct drum, kind of like the wear in the OD drum. Make sure the planet gears don't wobble on the pins, some up and down movement is normal.

 

[greg s]

Thanks again JK080. I will look at those areas closer. What part of North GA are you in?

 

[greg s]

Does anyone know the difference / correct bands for the intermediate and overdrive? I found 2 different numbers listed 4L5Z-7D034-AA and E6TZ-7D034-A and both are listed to fit the 5r55e.