Alfa Romeo Forums banner

Transaxel to rear g-bow

1K views 8 replies 4 participants last post by  Jerry Ehlers 
#1 ·
Trans and drive line in with all new parts. When the six nuts/bolts were tightened the rear g-bow formed into kind of a zig -zag shape, looking real wrong. Backed off the six bolts,rotated the drive line to see that the input shaft to the trans contacted the surface of the g-bow at 12 o'clock but had approx a 6mm gap at the bottom or 6 o'clock. Looks to me that the front of the trans needs to be shimmed up at the front to bring the two surfaces true to each other. Any thoughts?
 
#2 ·
Is this a GTV6 or a Milano?

Be sure the pinch bolt is loose at the front end of the drive shaft, as well as the rear transaxle mount bolt and the 6 dedion front cross member bolts when you go to position the transaxle flange against the giubo. Ie, the t/a may need to be slid forward a little bit to be flush with it. You definitely don't want the giubo bolts to pull it back towards the flange, giving the zigzag.

Bill
 
#3 ·
Transaxel to driveline

Thanks Bill! Actually I'm working on my 79 Alfetta GT. I did read something somewhere that there are two different front trans mounts; one with a "shim" at the base and one without. I have also heard about this pinch bolt that is important. Does an Alfetta have one of these? if so where exactly is it and what does it look like? This is my first Alfa so sorry if the answers to the questions are too obvious.
 
#4 ·
Hi Jerry,

I don't have any Alfetta experience, but I don't think the Alfetta has a pinch bolt up front. The front transaxle mounts that are still available are for the Milano and have an extra plate welded to the bottom which should be removed for use with a GTV6 (and presumably the alfetta too).

Bill
 
#5 ·
No pinch bolt on the Alfetta.
Shim/no shim front trans mount is a GTV6/Milano issue.

This issue comes up on the BB from time to time and when it has frankly, I've always thought something must be assembled incorrectly. Until recently that is, when it was noticed on my Alfetta. The body is slotted to accept the rear trans mount bolt so there is some adjustment there, but as you, I'm a bit of a loss to explain the difference. I was going to replace the rear engine mount next as it's a little buggard. Your comment about the angle was interesting as I've been focusing on the length. The angle would only seem to come into play if as you say, the front trans mounts were the wrong part as the carrier bearing postion (assuming new components here) is fixed.
I've been considering the possiblity that the new giubos are slightly narrower, but have no basis for this, other than I have a '76 front giubo (older style) and it is quite a bit thicker than a couple of newer ones, but the difference just might be by design and not a manufacturing change.

Hope your thread generates some good suggestion.
 
#6 ·
Jerry, can I assume the g-bow is the same as a do-nut?

Unfortunately no sliding shaft with pinch-bolt. Why oh why couldn't Alfa have installed a sliding section on the driveshaft just as they did on the Spiders is beyond me. I'm convinced the constant pulling and pushing on the three donuts is what destroys the donuts all too soon.

I'm also fairly convinced that the aftermarket donuts available are somewhat thinner than original so the entire driveshaft assembly ends up being too short.

The first thing you should check, is if there is room to move the entire transaxle forward a bit. Undo the single bolt/nut in the very upper rear (19 mm wrench/socket, pretty sure) and push forward. Not very elegant but I get on my back and push with my feet.

Drilling out the upper dogbone end plate's spot welds and moving them underneath will get the front mount up a bit.

If shaft is still short, I use cupped washers for shims to take up the slack. Be sure to do it on all three of the bolts.
 
#7 ·
Transaxel to driveline

Great input guys! I'm going to loosen everything up and see if I have some back to front movement. I still think that I will have a variance in mating surfaces that will require some vertical adjustment at the front of the trans but I'll see what happens when everything is free to move around a bit. Its very interesting to me regarding the observation about the new "donuts" or guibos possibly being thinner then OEM parts. The rear driveline does appear to be not fully seated in the trans input shaft, in effect, looking like this connection is maybe 6-7mm too short. I'll keep you posted. Thanks again for your help!
 
#8 ·
Jerry, it is possible that the mating end (hole) on the rear donut which fits over the end of the stub clutch flywheel is too small. If you have accurate calipers you could check it that way or else attach a few or several hose clamps around the donut and tighten so that the donut slips off, then hold it up to the end of the clutch shaft.

If too tight of a fit I'd try taking it down with coarse sandpaper on the donut hole (so to speak) rather than sanding down the clutch shaft.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top