Question: I just had a700r4 rebuilt with supposedly all performance parts and upgrades. It never shifted with a solid shift from the start and after about 10 miles it now has low gear only. upgrades were supposed to be from complete b@m rebuild kit. Is the trans burnt or just me?
Answer: You may be burnt, I don’t know you!! Hopefully the transmission you mention, a fully rebuilt Chevy transmission, T700R4 with the performance parts and B&M rebuild kit was installed at time of the rebuild, Who reinstalled the transmission is an issue. If the company removed it, rebuilt the transmission and reinstalled it, than go back and discuss it in a rational manner. Let them know your concerns. If they are on the level, you will be promptly taken care of.
No matter who installed the rebuilt transmission, there is a diagnostic process that should be followed. Because a 700R4 is not computerized it uses a governor and TV or throttle velocity cable instead of a computer and lots of inputs
Critical question: If you did your own installation, did you flush the cooling lines and the transmission cooling part of the radiator with a suitable agent? Did you clean the driveshaft yoke and dipstick? Automatic transmissions don’t deal with dirt well and if it was not flushed, chances are you need to remove the transmission and decontaminate it and flush the cooling system before it is reinstalled. If you had the rebuilding shop or supplier do the installation, then that is their concern, not yours.
If it established that the unit is clean and contamination is not a factor in terms of causing the valve body or brain of the transmission not to think properly, then I would suspect a transmission assembly mistake. The test that tells all is to go through a line pressure test. Checking how much hydraulic pressure the transmission is putting out in each separate gear range is critical to know in order to determine your next step.
To put it simply, (A.) The transmission has contamination in it. Causing the valves in the valve body and or governor to stick or drag, instead of ‘snap’ forward or backwards. Which would cause all sorts of shift maladies, including yours. (B.) The B&M rebuild kit and upgrade kits were not installed properly.
First off, personally, I don’t care for B&M products at all. When compared to other brands that really work, the B&M kits are over complicated and are hard to comprehend the installation directions. Lots of rebuilders skip steps or just don’t understand the kits. Bottom line is that a qualified rebuilder has to be able to read and have terrific comprehension skills to install update kits and understand directions.
That is my story and I’m sticking with it. Next time you need a beefed up T-700R4 call the most reputable rebuilt transmission supplier in the county, GotTransmissions.com… trust me on this, they have the detailed and time consuming procedures well established after years of locating and supplying folks with the best rebuilt T-700R4 or any transmission for that matter, on the market.
We have a few more T700-R4 articles that may be of interest to you. Enjoy them on our GotTransmissions.com blog. Specifically we have an article on the best updates and kits for a beefed 700R4.