Metallic rattle

[Obs addict]

Newly rebuilt 700r4 second time around first time I lost reverse after 100km…the transmission shop removed said clutch’s were stuck together and fixed under warranty. Got it back now there is a loud metallic rattling if I accelerate from about 30km but, nothing from a dead stop hard launch. When it does happen it starts loud then fades as then rpm increases. Took it back to the transmission shop went for a ride he looked at me bewildered when he heard the rattle and said what the heck is that. We put it on the lift looked the whole truck over for the source and didn’t figure anything out. I just put fresh u joints in and that did nothing need your help guys!

 

[NickTransmissions]

Newly rebuilt 700r4 second time around first time I lost reverse after 100km…the transmission shop removed said clutch’s were stuck together and fixed under warranty. Got it back now there is a loud metallic rattling if I accelerate from about 30km but, nothing from a dead stop hard launch. When it does happen it starts loud then fades as then rpm increases. Took it back to the transmission shop went for a ride he looked at me bewildered when he heard the rattle and said what the heck is that. We put it on the lift looked the whole truck over for the source and didn’t figure anything out. I just put fresh u joints in and that did nothing need your help guys!

Rattling is usually exhaust / exhaust heat shields, esp at higher speeds if they're loose. If it's internal trans it could be sun shell (that should have been replaced with an upgraded heat treated shell at minimum).

Thinking the builder inadvertently cut a machine-square cut seal on the low reverse piston first time and didnt catch it when air checking the L/R clutch or didnt air check).

Any symptoms other than the rattling?

 

[Obs addict]

I’m not sure about the sun shell but I will ask, he told be he put in a corvette servo etc. also running a higher stall converter as I have a built engine going in this fall. If it’s the shell than it will eventually break and I’ve been driving it hard but it only makes the noise when it’s being driven mildly and I believe only in second gear and it fades after about 10 seconds. Checked all the heat shields etc I can really feel it on the drivers floor and it appears to be coming from the transmission area under the truck. Could it be the governor? It has not shifted good twice, just revved up until I got off the gas then it engaged. The builder told me to drive it till it breaks then he will build me another…….

 

[NickTransmissions]

The builder told me to drive it till it breaks then he will build me another…….

Lol! I'd prob find another builder if that's what he's recommending...If the transmission is not shifting correctly, it should go back to him for repair/correction assuming it's under warranty...If one of my customers told me what you've relayed, I'd recall the unit for diagnosis and repair. That said, your shifting problems can be any or a combo of all these things:

1. TV cable not set up or adjusted properly - This is where I'd start first
2. Valve Body (TV valve sticking, TV plunger/sleeve leaking or worn)
3. Governor (gear in bad shape, governor bore worn/leaking - rare)
4. Worn pump/PR valve or boost valve/sleeve
5. Incorrect shift calibration
6. Leaking forward drum (drum will leak apply fluid at the base of the input shaft)
7. Leaking third acc check ball capsule (rare)

Did he do the installation or did you?

If you did, was the TV cable set up and adjustment validated through line pressure testing?