How do you mate the transaxle to the engine?

[Dennis Nicholls]

I'm about to throw in the towel.  I've spent 6 hours straight trying to mate the transaxle back to the engine in my car.

 

I've made a pair of "pilot bolts" by cutting the heads off a pair of 100mm bolts and cutting a screwdriver slot in the ends for eventual removal.  They were placed at locations "B" and "F" in the Pelican photo.

 

 

Using a HF transmission jack,  I've lifted the transaxle up and was able to get it started on the two pilot bolts.  It goes in until there is an approx. 30mm gap between the engine and tranny.  Then it just stops dead.   I've tried everything.  Wiggling it side to side.  Wiggling it up and down.  It just won't go in.

 

I was very careful with the clutch alignment tool,  holding the tool with one hand when starting to tighten the PP bolts down so that the alignment tool was in the center of its "wiggle range".

 

What's the trick?  I've wasted an entire day on this already.

Edited June 25, 2014 by Dennis Nicholls

[timbo]

I dont have any experience of fitting Boxster transmissions, but on a conventional set up I always found it useful to put the transmission into gear so that the main shaft could be rotated by turning the driveshafts. You might need to hold one side while you rotate the other.

[JFP in PA]

I'm about to throw in the towel.  I've spent 6 hours straight trying to mate the transaxle back to the engine in my car.

 

I've made a pair of "pilot bolts" by cutting the heads off a pair of 100mm bolts and cutting a screwdriver slot in the ends for eventual removal.  They were placed at locations "B" and "F" in the Pelican photo.

 

 

Using a HF transmission jack,  I've lifted the transaxle up and was able to get it started on the two pilot bolts.  It goes in until there is an approx. 30mm gap between the engine and tranny.  Then it just stops dead.   I've tried everything.  Wiggling it side to side.  Wiggling it up and down.  It just won't go in.

 

I was very careful with the clutch alignment tool,  holding the tool with one hand when starting to tighten the PP bolts down so that the alignment tool was in the center of its "wiggle range".

 

What's the trick?  I've wasted an entire day on this already.

 

Take a break and look at the engine and trans from all sides; quite often, we see problems due to either the trans or engine being slightly "off axis" with each other(it does not take much of an angle to cause an issue like yours).  The front surface of the gear box and the mating surface on the engine case must be parallel, and as Timbo commented, putting the gearbox in gear so you can slightly rotate the input shaft by turning the axel can help as well.

[Dennis Nicholls]

Yeah I pulled the tranny back off and checked to see if it's in gear.  By holding both output flanges I can rotate them both and cause the input shaft to turn. 

 

I put the cutch alignment tool back in for a second and it seems to fit just right.

 

Using blocks of wood I've tried to get the front surface of the tranny vertical on the tranny jack (using a bubble level).

[JFP in PA]

Quite often, I find that wiggling the trans slightly while pushing it towards the engine helps.  These things can be a pain in the butt to go back, or they simply just drop into place; like Forest Gump's box of chocolates, you never know what you are going to get. 

[kbrandsma]

Rotating the input shaft and push.  Here is a thread(link) on the 986 Forum with some discussion on the matter.

 

http://986forum.com/forums/performance-technical-chat/48316-transmission-installation.html

[JFP in PA]

It also helps if you have a very light coating of white lithium grease on the input shaft and throw-out bearing collar.

[Dennis Nicholls]

My LUK clutch kit came with a packet of "special" black grease for the input splines, so I used that.  Strange that a LUK clutch kit comes with OEM Sachs clutch disc and pressure plate - the numbers matched what came with my car.

[Dennis Nicholls]

Rotating the input shaft and push.  Here is a thread(link) on the 986 Forum with some discussion on the matter.

 

http://986forum.com/forums/performance-technical-chat/48316-transmission-installation.html

 

You don't know how ironic your posting is, considering my post #2 in this thread on the Miata forum a few weeks back:

 

http://forum.miata.net/vb/showthread.php?t=544688

 

The problem with the 986 is that the diff is built into the transaxle.  You have to spin both output flanges or the diff just spins without turning the tranny's output shaft.

 

My brilliant idea:  put a long bolt into one of the output flanges so it can't turn.  Then I'll have one hand to turn the other output flange and a free hand to push on the tranny.

 

EDIT  I got a long bolt out of my metric bucket and tested my idea....now I can spin the input shaft with only one hand on an output flange.  :thumbup:    The old "safecracker" Richard Feynman would be pleased.

Edited June 25, 2014 by Dennis Nicholls

[Jager]

I recommend installing the clutch slave cylinder before mating the transaxle to the motor completely. Give yourself a little gap between the transaxle and the motor and install the slave cylinder, then tighten the tansaxle/motor bolts. Otherwise you will be fighting the pushrod of the slave cylinder while trying to insert the slave cylinder mounting bolt.

[Dennis Nicholls]

I took Thursday off to recuperate.

 

Being able to spin only one output flange really helped.  All of a sudden the output flange would no longer turn - meaning the input shaft splines were locked into the clutch disc splines.  Then what prevented the tranny going in farther was that stupid stud at location "H".  I had to fuss a bit until it went into the hole in the engine case.  Then the entire tranny slid right in.

 

Jager,  I've read that before.  I'm leaving a small gap and will put in the clutch slave.  I'm taking a break now.