Clearance to pull a ZF6 out?
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,972
Likes: 243
Clearance to pull a ZF6 out?
Planning on a few things this winter, one of which will require the ZF6 to come out of the car. My dilemma is that I don’t have a dedicated transmission jack, I have one of those bulky adapters that fits I into a standard floor jack saddle. It works well, has been used for a truck that obviously has tons of height clearance and an awd Subaru - though for the Subaru the trans didn’t clear coming out, but it was just a clutch job so that was fine, just slid it back enough to do the work. For the ZF6, I want to be able to clear it from the car.
I have 6 ton jackstands, I believe they max around 20”. I don’t see any way that will give me the clearance I need with my transmission adapter that adds close to a foot in height.
For those that have pulled ZF6 without a lift - did you use 12t stands for extra height? Did you use a dedicated low profile trans jack? If the latter - is one with an articulating head (seems those are hydraulic) needed or will a scissor type (half the cost) work?
ps: this is all so I can pull the motor for a long awaited cam upgrade. The clutch is fine, but I have new components to install anyway, definitely keeping the DMF which isn’t making any odd sounds and call me crazy but I like how heavy flywheel cars drive on the street. Thinking about adding the input shaft shim from ZFDoc and replacing the tail shaft seal, which on my car has looked wet for years and occasionally has a single drop on it but not what I would call a leak.
I have 6 ton jackstands, I believe they max around 20”. I don’t see any way that will give me the clearance I need with my transmission adapter that adds close to a foot in height.
For those that have pulled ZF6 without a lift - did you use 12t stands for extra height? Did you use a dedicated low profile trans jack? If the latter - is one with an articulating head (seems those are hydraulic) needed or will a scissor type (half the cost) work?
ps: this is all so I can pull the motor for a long awaited cam upgrade. The clutch is fine, but I have new components to install anyway, definitely keeping the DMF which isn’t making any odd sounds and call me crazy but I like how heavy flywheel cars drive on the street. Thinking about adding the input shaft shim from ZFDoc and replacing the tail shaft seal, which on my car has looked wet for years and occasionally has a single drop on it but not what I would call a leak.
Drifting
Joined: Jan 2005
Posts: 1,354
Likes: 325
From: San Antonio Tx
I have a 1/4 inch thick flat plate 6" x 16" with a stub welded in the center that fits on my floor jack. I Used a couple of wooden wedges for tilt. That puts me 5" from the floor and I have walked the trans off and back on it if needed. I used a ratcheting strap to tie the transmission on to it just for safety.
Le Mans Master
Joined: May 2005
Posts: 7,354
Likes: 2,278
From: Central Maryland
I yanked mine with the car on a Kwiklift, using this Harbor Freight hydraulic transmission jack that's rated for 800 lbs:
https://www.harborfreight.com/800-lb...ack-60234.html
The ZF is a heavy beast (around 150 lbs, IIRC), and I wanted something that would handle it with good stability and maneuverability. The little scissor units just didn't seem like a good choice for the job. The HF unit I used worked well, and its minimum lift height of 8.5 inches should allow the trans to drop a bit closer to the ground than what you've used in the past. It also has two-axis tilt capability via hand screws.
I can't speak directly to your clearance issues with jackstands. The Kwiklift places the car approximately 20 inches above the floor (this is the distance to the bottom of the tires -- distance to frame would be greater). I couldn't get the transmission jack rolled out from under the car with the ZF on it, because of the Kwiklift ramps on each side, the Kwiklift's lift tube in the rear, and the cross-ramp bridge in the front that I had to use to support the rear of the engine while the C-beam was out. It was a real PITA working around the gearbox with it trapped under the car. I'd probably not do it that way again.
A few thoughts for your consideration:
Have you given any thought to pulling the trans and engine together, since you're planning to yank the engine, too? Or, if the cam swap is the only thing that's needed, you could consider doing it with the engine in the car.
If your tailshaft seal is leaking, check for radial lash between the front yoke of the driveshaft and the tailshaft of the trans. If you have any noticeable slop there, a new seal will likely fail quickly unless you also replace the bushing in the extension housing, and the front yoke if it's showing wear. Front yokes were in scarce supply when I needed one, but Bill Boudreau at ZF Doc found one for me. He also can cut down a yoke that's identical aside from its length, if you need one (might be for a Turbo 400, but my memory has grown hazy on this as it's been around 8 years since I was into all of this).
If your DMF is in questionable condition, consider a heavy steel SMF as a replacement (and, no, you're not crazy for liking a heavy wheel for street use. I do, too). I went with the Spec extra-mass billet steel SMF, and am pleased with it. The car launches pretty much the same as it did with the DMF, which is nice for street driving -- no need for excessive feathering of the throttle on uphill starts, etc. I also didn't end up with the can-of-rocks gear rattle that many have encountered with light-weight flywheels, and that was important to me. My car, being a ragtop, is a poor candidate for track use, and is strictly a street-driven car. I did all of this work on mine before Bill had come up with the shimming trick to minimize gear rattle.
Best of luck with it, however you opt to proceed.
Live well,
SJW
https://www.harborfreight.com/800-lb...ack-60234.html
The ZF is a heavy beast (around 150 lbs, IIRC), and I wanted something that would handle it with good stability and maneuverability. The little scissor units just didn't seem like a good choice for the job. The HF unit I used worked well, and its minimum lift height of 8.5 inches should allow the trans to drop a bit closer to the ground than what you've used in the past. It also has two-axis tilt capability via hand screws.
I can't speak directly to your clearance issues with jackstands. The Kwiklift places the car approximately 20 inches above the floor (this is the distance to the bottom of the tires -- distance to frame would be greater). I couldn't get the transmission jack rolled out from under the car with the ZF on it, because of the Kwiklift ramps on each side, the Kwiklift's lift tube in the rear, and the cross-ramp bridge in the front that I had to use to support the rear of the engine while the C-beam was out. It was a real PITA working around the gearbox with it trapped under the car. I'd probably not do it that way again.
A few thoughts for your consideration:
Have you given any thought to pulling the trans and engine together, since you're planning to yank the engine, too? Or, if the cam swap is the only thing that's needed, you could consider doing it with the engine in the car.
If your tailshaft seal is leaking, check for radial lash between the front yoke of the driveshaft and the tailshaft of the trans. If you have any noticeable slop there, a new seal will likely fail quickly unless you also replace the bushing in the extension housing, and the front yoke if it's showing wear. Front yokes were in scarce supply when I needed one, but Bill Boudreau at ZF Doc found one for me. He also can cut down a yoke that's identical aside from its length, if you need one (might be for a Turbo 400, but my memory has grown hazy on this as it's been around 8 years since I was into all of this).
If your DMF is in questionable condition, consider a heavy steel SMF as a replacement (and, no, you're not crazy for liking a heavy wheel for street use. I do, too). I went with the Spec extra-mass billet steel SMF, and am pleased with it. The car launches pretty much the same as it did with the DMF, which is nice for street driving -- no need for excessive feathering of the throttle on uphill starts, etc. I also didn't end up with the can-of-rocks gear rattle that many have encountered with light-weight flywheels, and that was important to me. My car, being a ragtop, is a poor candidate for track use, and is strictly a street-driven car. I did all of this work on mine before Bill had come up with the shimming trick to minimize gear rattle.
Best of luck with it, however you opt to proceed.
Live well,
SJW
Last edited by SJW; Sep 15, 2018 at 03:15 PM.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Big fan of heavier FW on the street also even when they make some RPM...if you run a tall gear Id really avoid a light one it just sucks period.
Low gears or lots of cubes perhaps. Dont think its worth sacrificing any driveability at all for the sake of a few hp maybe? It revs faster big deal.
Others love them and wouldnt have anything else. If you arent sure try driving one youll know right away.
Low gears or lots of cubes perhaps. Dont think its worth sacrificing any driveability at all for the sake of a few hp maybe? It revs faster big deal.
Others love them and wouldnt have anything else. If you arent sure try driving one youll know right away.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
I’ve pulled manual and auto trannies from under my 84 dozens of times while on jackstands. I just use a regular jack with. 8’ square platform above the jack to support the transmission. After the transmission is out, lower the jack all the way down and roll the tranny off the jack front of the jack or off the side. . The tranny then can be wiggled out from under the car. I always work alone and I have carpet under my car which makes it more comfortable than lying in cement.
Racer
Joined: Mar 2003
Posts: 346
Likes: 33
From: OKC OK
when I pulled mine I use the same jack SJW linked to. I also used 6 ton stands. I used a rubber mallet to flatten the seam to give a little more room to get the torque arm out. When I went to reinstall I cut the heads off 2 bolts and put screwdriver slots in them. Screw them part way into the bellhousing so you can rest the front of trans on them. It makes it a little easier to get the input into the clutch
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,972
Likes: 243
Thanks for the replies everyone! Certainly gives me some insight and options. I have a small MIG that I’ve used to do exhaust work primarily that I can fab a plate up for a floor jack but I was mostly considering the 2 offerings from Harbor Freight. A scissor type with no tilt adjustment and a more expensive hydraulic unit that also tilts, they’re rated 400 and 800 lbs, respectively. Either way I still don’t feel like the 6 ton stands will give me the clearance I need, especially if the shifter is in place. I can buy 12 ton stands but that adds considerable more expense in tools. Anyone know the height of the ZF6 from bottom to top of shifter stalk?
I’d love to pull the engine/trans together but didn’t think it was so possible in a C4. It is a 94 LT1 car and I do own the “happy hooker”. I still didn’t think it would be possible - especially since I want to pull it from the side, leaving the hood on. I know, I know... the hood is easy to remove right... well I’m a one man operation and even with an extra set of hands I feel like lining it back up for reinstall would be a nightmare. Let alone worrying about scratching or damaging it.
Definitely want to revisit the tailshaft comments when the time comes - I’ve heard there is a bushing in it (bronze perhaps) that can cause issues.
I’d love to pull the engine/trans together but didn’t think it was so possible in a C4. It is a 94 LT1 car and I do own the “happy hooker”. I still didn’t think it would be possible - especially since I want to pull it from the side, leaving the hood on. I know, I know... the hood is easy to remove right... well I’m a one man operation and even with an extra set of hands I feel like lining it back up for reinstall would be a nightmare. Let alone worrying about scratching or damaging it.
Definitely want to revisit the tailshaft comments when the time comes - I’ve heard there is a bushing in it (bronze perhaps) that can cause issues.
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
When I repalced the clutch in my 94' all I did was jack the car up, and put (4) 2x12 under each tire. I screwed them all together. Then I just used my floor jack from the back of the car to lower the trans. Worked like a charm and had plenty of room. I believe I put the transmission in 3rd or 4th to clear the tunnel opening. Really not a hard job looking back on it.
Last edited by TorchTarga94; Sep 16, 2018 at 10:45 AM.