Hello all, I have a 1985 Vette, and the 700R4 only has 1st and reverse. It gave no signs of a malfunction, it just stoped working. I have read a lot of messages about the 700R4 and no one seems to like them. My question is can i put a TH 400 in this car? What type of modifications will have to be done? I understand there will be no O/D and the fuel mileage will suffer. but i am willing to deal with that. CAN THIS BE DONE?????

 

I also would like to know about this. I just had my 700R4 rebuilt and am not that happy with it. Well, it's not that I am really not happy with it, I just think that it could be a whole lot better. The guy did it right but I have had cars with the th350 and 400 in them and I like that tranmission a whole lot better. Thanks

 

hay guys,i am not a big fan of the 700R4 eather, but it is a good tranny, it is the only one that chevy makes that will handle power with overdrive,and to your question yes it can be done,a 350 or 400 can beinstalled,but you dont need a 400 in a small block,a 350 will be plenty of tranny,parts are cheep to, to do this swap u will have to find out if you have a long or short tail shaft,befor you buy the 350.keep in mind that u will not have that 4 gear no more, and your gass milage will be gone,and it will always feel like you have to shift it again,i have a 700R4 in my vette and it is great i installed a shift kit and a 2000 stall converter and did some pump up grades, it will shift just like a 350....now things will be diffrent changing over to the 350, like speed odomitor hook ups. you mite have to do some mods,and on the 700R4 on the vette's they do not use tranny mounts it is a solid beam that hold's the tranny up.all you have to do is buy a new converter 1500-2000 stall a new flex plate and a shifter b&m,then just modify stuff to get it in.i can do it for you if you live in florida,it will cost you about 2500.00 dollers and i will supply all the parts and tranny,

 

redsox. sounds like your shifter linkage or valve body is malfunctioned.drop the trany pan and see if any part are laying in the pan or broken,then buy a b&m trans pack and rebuild the valve body,they will give you all instuctions, you will be able to chose from heavy duty mode to street and strip to full manual shifting,cost some were a round 150.00 bucks,summit has the kit,and check your shifter cable and check the bracket that bolts on the tranny could be loose,

 

Thanks for the info, i will check the pan for parts, If that dose not help i will look into the TH 350 or 400. I appreciate the advice.

 

you are wellcome.

 

First you must determine if the transmission is damaged inside or not. If you have access to a oil pressure gauge thread it into the fitting just above the shift linkage. Start the car and see what the pressure is. It should be about 80 psi or slightly less at idle in drive. If it is really high you have a number of things that can cause this. If the pressure is normal I would remove the governor cap from the drivers side of the transmission. It is towards the rear and usually black in color about 4 inches across. Pull the governor out and look at the plastic gear on the end. If it looks apple cored(fancy term for the center of the gear being chewed out) get another gear and seal for the cover and reassemble it. You should be up and running. As far as the 700R4 not being a good transmission I would disagree. With the right work it is a great transmission. If you don't have access to a pressure gauge just remove the governor and check that. Make sure that your tv cable is connected at the top and also if you are pressure testing it make sure your gauge can handle at least 300 psi. Hope this helps. Rich