V6/LS Firebird swap - longer slip yoke or DS?
05-11-2017, 01:31 PM
#1
Teching In
Thread Starter
V6/LS Firebird swap - longer slip yoke or DS? Will make this short as possible, which I noticed now will not be really short.
Got the LQ4/4l60e in my 98 firebird V6 orig car now.
4l60e was out of an 01 S10. It has the shorter bell housing and no 12 o-clock bolt hole so technically it is shorter than the LS style that come in the 4th gens.
Anyways, the slip yoke now sticks out just shy of 1/2" from it did before. It's on jack-stand so the rear is just hanging. It would go into the trans, connect to rear yoke and stay engaged like this. I jacked up rear diff to make it act like it is on the ground and marked it. I then removed the driveshaft to see how far the yoke is on the output shaft. It sits about 1.5" on the output shaft in the trans. I know most people say the yoke should sit 2 1/4 - 2 1/2" minimum on the splines. Well if that is the case then it was never sitting right in there stock (would only be 2" on the splines).
My main question is should I get a longer DS made or get a longer yoke to make up that 1/2" that it is now out of the trans? The yoke is about 6 1/4" from center of joint to end of shaft. I see some places have 7.5" yokes. According to how much should be on the splines in the first place in the trans and based on how much I lost a I should be fine with a 7.5" yoke. See my crappy reasoning below.
- Yoke 1/2" further out of trans now than with stock 4.60e/3.8 combo
- Current yoke sitting only 1.5" total on output shaft of 4l60 trans
- This means the original must have only been about 2" on the output shaft. If it should be on at least 2 1/2" than I need to add another 1/2" at least. That means adding a full inch to the yoke.
- If the current yoke is 6 1/4" from center of joint to end of shaft, and adding a full 1" to it, we have a yoke of 7.25" I don't see how an extra 1/4" on the output shaft should make a difference.
I also pushed the shaft in all the way until it bottoms. It has plenty of room to go in there. It backs out over 2" for sure from bottoming out, probably close to 3 inches.
Other question is will this extra 1/2" out further from trans effect anything in the drive train (u joints, DS, etc)?
Hopefully this is not confusing. I can add pictures later tonight when I get at it again. Thanks!
Got the LQ4/4l60e in my 98 firebird V6 orig car now.
4l60e was out of an 01 S10. It has the shorter bell housing and no 12 o-clock bolt hole so technically it is shorter than the LS style that come in the 4th gens.
Anyways, the slip yoke now sticks out just shy of 1/2" from it did before. It's on jack-stand so the rear is just hanging. It would go into the trans, connect to rear yoke and stay engaged like this. I jacked up rear diff to make it act like it is on the ground and marked it. I then removed the driveshaft to see how far the yoke is on the output shaft. It sits about 1.5" on the output shaft in the trans. I know most people say the yoke should sit 2 1/4 - 2 1/2" minimum on the splines. Well if that is the case then it was never sitting right in there stock (would only be 2" on the splines).
My main question is should I get a longer DS made or get a longer yoke to make up that 1/2" that it is now out of the trans? The yoke is about 6 1/4" from center of joint to end of shaft. I see some places have 7.5" yokes. According to how much should be on the splines in the first place in the trans and based on how much I lost a I should be fine with a 7.5" yoke. See my crappy reasoning below.
- Yoke 1/2" further out of trans now than with stock 4.60e/3.8 combo
- Current yoke sitting only 1.5" total on output shaft of 4l60 trans
- This means the original must have only been about 2" on the output shaft. If it should be on at least 2 1/2" than I need to add another 1/2" at least. That means adding a full inch to the yoke.
- If the current yoke is 6 1/4" from center of joint to end of shaft, and adding a full 1" to it, we have a yoke of 7.25" I don't see how an extra 1/4" on the output shaft should make a difference.
I also pushed the shaft in all the way until it bottoms. It has plenty of room to go in there. It backs out over 2" for sure from bottoming out, probably close to 3 inches.
Other question is will this extra 1/2" out further from trans effect anything in the drive train (u joints, DS, etc)?
Hopefully this is not confusing. I can add pictures later tonight when I get at it again. Thanks!
Last edited by codemanrose; 05-11-2017 at 01:50 PM.
05-15-2017, 07:31 PM
#2
Teching In
Thread Starter
Got it. Summit sells the perfect size for this. They have a 6.75" yoke, which is almost spot on exact difference. So anyone that is doing an early 4l60e or LT style 4l60e to LS in a 4th gen know it will be about 1/2" shorter max. 6.75" yoke will fit. Will be interesting if it causes any vibration or drivability difference having that extra 1/2" yoke and the Driveshaft being 1/2" further way from transmission. I doubt it will but we will see.