84 4+3 Trans Questions
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,202
Likes: 3
From: MD
84 4+3 Trans Questions
Ok, so I'm removing the 4+3 trans from my 84 Z51 this coming Saturday and I've got a lot of questions.
First of all, does anyone have any tips/tricks for taking it out. I have a shop manual and I'm assuming that it will give me the necessary steps to unhook everything and get it out.
Secondly, the transmission has some issues and I want to know if I should/could fix some of this stuff while it's out. The transmission has trouble going into first gear a lot and sometimes second. It doesn't grind, it just starts to go in and then gets stuck. Sometimes you can force it through and it will pop and go in, sometimes you have to pull it back out and try several times. I have read that this is caused by the reverse lockout rod? While the trans is out can I get to the linkage and is there a way to revive it. If not, does anyone have a set of good linkage for sale? Could this problem be the trans and not the linkage?
Also, while the trans is out, is there anything I can do to make it stronger. I'm building a 350 hp 400 ft. lb. engine for the car. I had heard on this forum about "welding the bearing" in the overdrive? Anyone using aftermarket shift linkages? I heard that the trans can torque in the mounts and bend the stock linkage.
First of all, does anyone have any tips/tricks for taking it out. I have a shop manual and I'm assuming that it will give me the necessary steps to unhook everything and get it out.
Secondly, the transmission has some issues and I want to know if I should/could fix some of this stuff while it's out. The transmission has trouble going into first gear a lot and sometimes second. It doesn't grind, it just starts to go in and then gets stuck. Sometimes you can force it through and it will pop and go in, sometimes you have to pull it back out and try several times. I have read that this is caused by the reverse lockout rod? While the trans is out can I get to the linkage and is there a way to revive it. If not, does anyone have a set of good linkage for sale? Could this problem be the trans and not the linkage?
Also, while the trans is out, is there anything I can do to make it stronger. I'm building a 350 hp 400 ft. lb. engine for the car. I had heard on this forum about "welding the bearing" in the overdrive? Anyone using aftermarket shift linkages? I heard that the trans can torque in the mounts and bend the stock linkage.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
"The transmission has trouble going into first gear a lot and sometimes second. It doesn't grind, it just starts to go in and then gets stuck."
If the internals , selector forks and syncros ,etc are good them problem could be in linkage adjustment which can only be done with trans in car as shifter mounts to body.
Removal is no different from normal.Have to remove exhaust /support trans / remove C beam and driveshaft /disco wiring ,remove clutch line , trans cooler lines/ support rear of engine / lower trans.
If not using hoist need at least 18' under sill if removing bellhousing with trans
If the internals , selector forks and syncros ,etc are good them problem could be in linkage adjustment which can only be done with trans in car as shifter mounts to body.
Removal is no different from normal.Have to remove exhaust /support trans / remove C beam and driveshaft /disco wiring ,remove clutch line , trans cooler lines/ support rear of engine / lower trans.
If not using hoist need at least 18' under sill if removing bellhousing with trans
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The 4-speed portion is a Borg-Warner Super T-10 so any good tranny shop can provide some heavy-duty internals. 350-400 ft-lbs should not be a problem for the 4-speed portion as the T-10 can easily tak e that.
The 4+3 was used behind the 87 and 88 Callaway twin-turbo cars (RPO B2K) and those motors were capable of 450+ ft-lbs of torque.
Go HERE for some info on the 4+3 and it's quirks and issues. S-K Speed in New York is supposed to be a good place to get parts and work done.
One important thing about the OD is to change the ATF and filter every 12K miles or so. Use Dexron II/III and a new filter. The filter is the same one that was used in Ford FMX tranmissions in the mid-70's to early 80's They came in Cougars, some Mustangs, Torino's and some F-150's. They should run about $5-$8 at parts stores compared to the $20 plus shipping from the Vette accessory catalogs.
The 4+3 was used behind the 87 and 88 Callaway twin-turbo cars (RPO B2K) and those motors were capable of 450+ ft-lbs of torque.
Go HERE for some info on the 4+3 and it's quirks and issues. S-K Speed in New York is supposed to be a good place to get parts and work done.
One important thing about the OD is to change the ATF and filter every 12K miles or so. Use Dexron II/III and a new filter. The filter is the same one that was used in Ford FMX tranmissions in the mid-70's to early 80's They came in Cougars, some Mustangs, Torino's and some F-150's. They should run about $5-$8 at parts stores compared to the $20 plus shipping from the Vette accessory catalogs.
