X1/9 Transmission installation problems

[rcarlson2bx]

I'm having problems re-installing the 5-speed transmission on my '81 FI X1/9. I have the rear A arms out and the car is on jack stands. The transmission will not mate to the engine block because the bump-out for the CV joints is hitting the rear frame cross-bar. I made a drift pin and placed it in the upper forward bolt hole, and can see that the transmission needs to rotate about 10 deg counter-clockwise to get the upper rear bolt hole and the lower rear stud to line up. I think the problem is that the engine, which is still in-place, has rotated and that' s what is causing the misalignment. Should I remove the reaction rod to make it easier to get things to align? Any other suggestions or guidance? Thanks in advance.

 

[EricH]

The engine flops around a fair amount when not held by the transmission mount. However you are supporting the engine, chances are you can shift it around by moving whatever is currently supporting it. You should not have to remove the dog one, and if you do you run the risk of the engine slipping into an even more unhelpful position.

 

[Rupunzell]

I'm having problems re-installing the 5-speed transmission on my '81 FI X1/9. I have the rear A arms out and the car is on jack stands. The transmission will not mate to the engine block because the bump-out for the CV joints is hitting the rear frame cross-bar. I made a drift pin and placed it in the upper forward bolt hole, and can see that the transmission needs to rotate about 10 deg counter-clockwise to get the upper rear bolt hole and the lower rear stud to line up. I think the problem is that the engine, which is still in-place, has rotated and that' s what is causing the misalignment. Should I remove the reaction rod to make it easier to get things to align? Any other suggestions or guidance? Thanks in advance.

Get two really long (no less than 100mm) M12x1.25 hex head cap screws/bolts, cut the heads off, add a slot or similar internal wrenching feature and cone this end, grease up and install these modified M12 threaded pins into the two M12 threaded holes on the block. Use these two M12 pins to hang the transaxle on while moving the transaxle towards the motor clutch assembly. Put the transaxle in any gear, then rotate both CV output flanges to move the input shaft aiding alignment with the clutch disc. Once it's all lined up, the transaxle will slide in.

~Make sure the clutch disc is properly lined up. There is no pilot bearing on the input shaft or crank end.

~Don't worry about the CV joints or their current location/status. Just keep them covered with a stout plastic baggie preventing dirt and etc from entering... once the transaxle is back in place, it the CV joints will go on.

~It will help to remove the lower cross member, as this will improve the possible angles of installation and all related. Support the motor properly once the lower cross member is removed only the front "snail mount" and top torque reaction bar supports the motor..

Bernice

 

[Steve Hoelscher]

The engine has shifted rearward. If you are using a jack/stand to support the engine, move it forward to gain clearance.

 

[rcarlson2bx]

Thanks all, I'll start by moving the engine forward and let everyone konw what happens.

 

[rcarlson2bx]

I managed to move the engine forward and the diff housing now clears the rear crossbar. I'm at the point where the rear stud is just engaging its mount hole and there are studs on both upper bolt holes. I'm guessing that the drive shaft is now about to being entering the clutch//crankshaft splines. I used the fiat alignment tool when installing the clutch and it goes in and out easily. I need an inspection mirror to see how far the drive shaft is from the clutch, is there any other way to tell?
Rich

 

[Bjorn Nilson]

I've found it easier to mate the trans with engine if removing the right CV flange during the operation. Having two "hanger bolts" also helps a LOT.

 

[SuperTopo]

Any angular misalignment will "jam" the input shaft in the clutch and NOT slide. Most people think it's the splines "not being aligned". Not really. There's a super generous lead-in on the shaft that actually works.

It's the fact that you are trying to slide the tranny on at an angle that jams it. Last time I installed a gearbox (like 3 weeks ago), I used a come-along from the rafters to lift the tranny by one of the clutch slave mounting bolts, then using the come-along I made sure it was straight in one axis and then wiggled it back and forth in the other and it slipped in when the alignment was right. Took like 5 minutes to slide it on, going back and forth and eye-balling the parallelism of the bellhousing to the engine block face.

Next time I do this I'm going to try the "M12 bolts as guides" trick. I've never tried that before. Back in the day, I use to get under the car and bench press the tranny up and slide it in place. Oh to be young and strong again...

 

[JKIDD]

When I did my clutch some 30 years ago, I struggled for hours trying to get the trans to line up. I had it in, out, rechecked the clutch alignment, nothing worked. Packed it in for the night in frustration. Next morning I went back to the garage, took a deep breath and CLUNK, slid right in. + 1 on the alignment bolts in the top holes. An old Fiat tech shared that with me when I told him my struggle.

 

[twincam69]

Alignment bolts/studs are the key….. it makes it so much easier when you have to do it again when you’ve put the disc in backwards.

 

[Steve Hoelscher]

A couple of important notes:

1) Common alignment tools don't work very well. This is because the engine's crankshaft doesn't have a pilot bearing. There is only a simple depression machined into the end of the crank. Most transverse transmission configurations do not use a pilot bearing as they are used primarily to support the input shaft of an inline transmission. The transverse transmission has the input shaft supported at both ends by roller bearings and has no need for a pilot bearing. Most alignment tools have an insert made to position in a pilot bearing. If you don't know this when performing the alignment you will likely have the clutch out of position. I use an old input shaft as the nose of the shaft is machined to fit the cup in the end of the crankshaft. It must be held in position as the pressure plate is torqued or the clutch will not be aligned. If you don't have an input shaft a 3/8th inch socket extention works in a pinch.

2) These transmissions either go right in or they don't. If its not falling into place, pull it back and start again. Don't ask me why. I occasionally stuggle with it just as everybody else does.

 

[SuperTopo]

A couple of important notes:

1) Common alignment tools don't work very well. This is because the engine's crankshaft doesn't have a pilot bearing. There is only a simple depression machined into the end of the crank. Most transverse transmission configurations do not use a pilot bearing as they are used primarily to support the input shaft of an inline transmission. The transverse transmission has the input shaft supported at both ends by roller bearings and has no need for a pilot bearing. Most alignment tools have an insert made to position in a pilot bearing. If you don't know this when performing the alignment you will likely have the clutch out of position. I use an old input shaft as the nose of the shaft is machined to fit the cup in the end of the crankshaft. It must be held in position as the pressure plate is torqued or the clutch will not be aligned. If you don't have an input shaft a 3/8th inch socket extention works in a pinch.

2) These transmissions either go right in or they don't. If its not falling into place, pull it back and start again. Don't ask me why. I occasionally stuggle with it just as everybody else does.

I'll add that the alignment of the clutch doesn't need to be within microns. I used a rod that fit within .5mm in the clutch. The clutch alignment has little to do with the transmission sliding on, you need to be visibly off for the transmission to not slide on the last 2-3 mm. If you're stuck and still see a 1/2" gap between the bellhousing and the block, it has nothing to do with the clutch alignment.

 

[Yves]

A couple of important notes:

1) Common alignment tools don't work very well. This is because the engine's crankshaft doesn't have a pilot bearing. There is only a simple depression machined into the end of the crank. Most transverse transmission configurations do not use a pilot bearing as they are used primarily to support the input shaft of an inline transmission. The transverse transmission has the input shaft supported at both ends by roller bearings and has no need for a pilot bearing. Most alignment tools have an insert made to position in a pilot bearing. If you don't know this when performing the alignment you will likely have the clutch out of position. I use an old input shaft as the nose of the shaft is machined to fit the cup in the end of the crankshaft. It must be held in position as the pressure plate is torqued or the clutch will not be aligned. If you don't have an input shaft a 3/8th inch socket extention works in a pinch.

2) These transmissions either go right in or they don't. If its not falling into place, pull it back and start again. Don't ask me why. I occasionally stuggle with it just as everybody else does.

My alignment tool like Steve mention "Old input shaft"

 

[Rupunzell]

Many decades ago PBS sold clutch disc alignment "tool" made from knackered input shafts..

These have a small step turned by lathe on the end measuring 0.717" OD from the spline OD.. This reduced OD area fits into the hole at the end of the crank. Clutch disc alignment does not need to be uber critical, just reasonable.

Bernice

 

[Steve Hoelscher]

I didn't know PBS sold those!

And yes, the disk doesn't have to be perfectly aligned. The problem is that its common to stick the alignment tool in the pilot bearing and let the bearing locate the tool and disk while you tighten the pressure plate bolts. This doesn't work with the X1/9 clutch as the alignment tool doesn't positively locate the disk. The weight of the disk will drag it out of position and then the input shaft will likely be out of position with the disk's splines.

Its easy to check alignment with a penlight.

 

[rcarlson2bx]

Success!!! I got the transmission reattached to the engine block this morning. Yesterday I went out and bought a 1T engine hoist. I humg the trnasmission on this using the slave cylinder bolt hols and got everything aligned. A sharp shove with my foot and it slid right in. Previously I was using a transmission jack and that just wasn't letting me move things around enough to get the alignment right. Thanks again for all the help and guidance Rich

 

[Rupunzell]

Success!!! I got the transmission reattached to the engine block this morning. Yesterday I went out and bought a 1T engine hoist. I humg the trnasmission on this using the slave cylinder bolt hols and got everything aligned. A sharp shove with my foot and it slid right in. Previously I was using a transmission jack and that just wasn't letting me move things around enough to get the alignment right. Thanks again for all the help and guidance Rich

Excellent, transmission jacks do not allow ease of movement. That alone could cause the difficulty of re-installing the transaxle.

FYI, some transaxles (Saab, now GM) have an internally threaded boss for a lifting ring that balances the transaxle about its weight center. This allows the transaxle to be supported mostly centered with movement to allow installation to the motor.. This plus using two alignment pins to the motor and reasonable alignment of the clutch disc makes a real difference for gear box install.


Bernice

 

[Dan Sarandrea (Phila)]

One more point that may help someone in the future who's reading thru this thread. On 1500 cars, some have reported that the right side output flange of the transaxle may foul the right/rear "ear" of the engine block. If that's the case, just remove the drive axle flange from the transaxle, install trans, then replace the drive axle flange. If your transaxle happens to be filled with lube, be ready for the spill.

 

[PaulD]

Excellent, transmission jacks do not allow ease of movement. That alone could cause the difficulty of re-installing the transaxle.

FYI, some transaxles (Saab, now GM) have an internally threaded boss for a lifting ring that balances the transaxle about its weight center. This allows the transaxle to be supported mostly centered with movement to allow installation to the motor.. This plus using two alignment pins to the motor and reasonable alignment of the clutch disc makes a real difference for gear box install.


Bernice

Years ago someone (Papa Tony I think) suggested using a strap set to the balance point on the transmission, and lifting it with a rope from overhead (I use a multi-pulley lifting set up so it lifts easily). It works for me just as Bernice suggests, including manoeuvring past the output flange.

 

[nichol01]

using a strap set to the balance point on the transmission, and lifting it with a rope from overhead

When I installed my throwout bearing upside down. I had to remove the trans to fix. I used these two bolts. I cut the heads off two head bolts. Then put slots in the end for easy removal with a screwdriver. And put them in the two top bolt holes in the block. Then as suggested by another member I used two ratchet straps secured to an overhead chain attached to a beam. By using two straps you can ratchet up and down each strap to center and orient the trans. Once I got mine lined up it went it in right away. The straps hold all the weight and just swing it in.