UN5 transaxle alignment

[Brian Wilson]

My GTD40 was fitted with an upgraded UN5 transaxle some years ago, replacing a UN1. Before I owned it. Was investigating a clutch problem recently, and discovered that the input shaft has almost 3mm of vertical movement (none in other directions). No symptoms in driving, but looks like a problem with alignment. Surprised it hasn't disintegrated.

It's attached to a fairly mild 302 Windsor.

Has anybody fitted a UN5? Any problem with alignment? It looks like the UN1 adapter is still there, but the UN5 bell housing may have been modified for some reason.

What do the experts think?

Haven't looked inside the box yet, but assume it's not pretty and likely to be damage to the input shaft bearing housing. Possibly need a new box. Should I consider going back to the UN1? I think I can get another UN5 here, but concerned there may be a fitment problem I don't know about.

Any advice gratefully received!

 

[Doug S.]

My GTD40 was fitted with an upgraded UN5 transaxle some years ago, replacing a UN1. Before I owned it. Was investigating a clutch problem recently, and discovered that the input shaft has almost 3mm of vertical movement (none in other directions). No symptoms in driving, but looks like a problem with alignment. Surprised it hasn't disintegrated.

It's attached to a fairly mild 302 Windsor.

Has anybody fitted a UN5? Any problem with alignment? It looks like the UN1 adapter is still there, but the UN5 bell housing may have been modified for some reason.

What do the experts think?

Haven't looked inside the box yet, but assume it's not pretty and likely to be damage to the input shaft bearing housing. Possibly need a new box. Should I consider going back to the UN1? I think I can get another UN5 here, but concerned there may be a fitment problem I don't know about.

Any advice gratefully received!

Just curious...wouldn't the end of the input shaft have inserted into a pilot bearing that would have been housed in the rear crankshaft flange? That would have supported it, hopefully in correct alignment, and you may have much less damage than expected.

I once replaced an automatic transmission with a standard transmission/clutch assembly...did not know about the need for a pilot bearing. It was in what we called a "dune buggy", essentially the frame and drivetrain of a car without the body (did have a roll bar, though), shortened by 3' and fitted with wide rims and low pressure tires...essentially a very lightweight load on the transmission. We used them for races in an old dry creek near my hometown. Despite all the abuse I heaped on that old Ford, there were never any problems with the transimission. I hope your transaxle has been as robust!

Cheers!

Doug

 

[Brian Wilson]

Thanks Doug. Yes I know what you mean but I don't think the shaft is supported at the front - just locates in the clutch centre. Will have a closer look today. These UN5 transaxles are used in buggies here too. Apparently unbreakable in those - with low weight and generally don't run V8s so less torque to deal with. I don't think strength is the problem here. Yours buggy sounds like fun. Cheers