#&%@ - DPO stripped the engine mount bolt

[dinghyguy]

Is the cross member symmetrical? could it be backwards? seems unlikely but...….

cheers
dinghyguy

[tdskip]

Hello gentlemen - got the mounts back on the correct sides and it looks better positioned now BUT I need to see how the transmission mount lines up now.

Had to pull the radiator out (again) to adjust the mounting bracket.

[RRoller123]

I have no idea how it is on the older cars, but on the newer cars (mine is '80), the transmission support yoke is NOT symmetrical, it must go on the correct way, or the trans will be shifted off the longitudinal centerline of the car. It is visually subtle, but if you measure the distance between the various mounting holes, you will see what I mean.

[tdskip]

EXCELLENT TIP - since I have loosened that yoke and have to install a new mount anyway now is the time to make sure it is correct. As it sits now it looks off to my eyes, which is to say it is canted to one side.

I have two sets of studs under the car where the yoke attaches to the bottom of the car. The car had the yoke on the rear most set of studs but am wondering if I should be using the forward set now? With the engine back to it's correct more forward position I am thinking I'll need to spend some time seeing how the transmission support all lines up now.

Thanks!

[18Fiatsandcounting]

On the earlier cars, the transmission rear support bracket has a curve on one side, and this is to provide clearance for the exhaust pipe. So, the curved side of the bracket should be on the passenger side.

This bracket should be installed on the two rear-most studs, and my understanding is that the front studs are used for different transmissions (like an automatic).

Of course, given all the other issues you've found, at this point I would question almost everything in terms of whether something you come across in your '68 is the way it is supposed to be...

-Bryan

[tdskip]

Thanks Bryan - so that part the DPO did not screw up then.

[tdskip]

Swapped the trans mount out - one of those nuts was FUBAR so replacing the hardware on it and then I'm ready for the drive shaft.

Who wants to start a bet on if it fits now?

[18Fiatsandcounting]

My bet is that you will get it fixed.

-Bryan

[tdskip]

Well, not fixed.

With the new transmission mount in I picked up enough clearance so the driveshaft metal yoke can line up with the transmission without fouling now BUT no way to fit it with the guibo.

When I was under the car yesterday it occurred to me that an improper length driveshaft would account for the problems I am having and when I looked at the driveshaft it looks like someone has been in there. There are some non-factory looking goober welds new the sliding spline...

Question: how much clearance should I have between the sliding spline yoke assembly and the front part of the drive shaft. In other works, is there an inch or more of space between the slide spline and the main part of the front driveshaft. In other-other words: is there an inch or more of travel before it is fully seated rearward?

Thanks!

[18Fiatsandcounting]

Well, I'm losing the bet so far...

I'm not sure I fully understand your questions. But, here's an answer: The splines on the narrower diameter (1" or so) section of the front driveshaft are about 3 or 4 inches in length. The splined section of the rear yoke should be able to slide all the way back to the end of the splines, and at that point, the rear of the splined section of the yoke would be about an inch or two away from where the front driveshaft transitions from the smaller diameter (1") to the larger diameter (3").

One of the aspects of the torque tube arrangement used in '68 spiders was there was an issue with cracking (not sure where), and so that's one reason why Fiat transitioned to the typical driveshaft arrangement in '69 and beyond. Maybe your car had some issues with cracking, and the original owner had to do some butchering to get everything to work again, including changing the length the driveshaft, moving engine mounts, etc. Could that be what's going on?

You know, compared to the amount of time you've spent on this already, moving the rear axle backwards an inch or so shouldn't be that hard. Put the body of the car on jackstands so the rear tires are off the ground. Remove one end of each of the 4 upper and lower locating rods, and perhaps the Panhard (transverse) rod. At that point, there should be enough play to allow you to push the rear axle backwards an inch or so. Essentially the rear axle is just hanging by the springs and shocks at that point. Although I didn't think this approach was necessary a couple weeks ago, maybe we need to revisit this.

-Bryan

[tdskip]

Thank Bryan - I'm pretty convinced my driveshaft has been messed with, non-factory weld debris on the front side of it.

I've already pulled it, so now would be the time to get it shortened.

Sorry for not being clear - when mounted on a properly set up car how much travel should be available to the sliding yoke before it bottoms out fully rearward? How much gap should there be between the non-moving driveshaft main body and the sliding yoke? Sounds like there should be several inches of available travel.

Rear axle idea: if I do that wouldn't the issue manifest in other ways once I mounted it up? In other words if the driveshaft is too long them moving axle back to mount and then moving it forward again would just bind the too long driveshaft up and destroy the new guibo, no? Love it idea - really appreciate the help - just not sure if that solves the issue.

[18Fiatsandcounting]

Sorry for not being clear - when mounted on a properly set up car how much travel should be available to the sliding yoke before it bottoms out fully rearward? How much gap should there be between the non-moving driveshaft main body and the sliding yoke? Sounds like there should be several inches of available travel.

The rear yoke should be able to slide all the way along the splined part of that front driveshaft, so 3 or 4 inches. When the yoke is slid all the way back, I think it's a couple inches from the larger diameter part of the front driveshaft.

I agree with you about the rear axle and driveshaft and maybe we need to find out what's really going on. I'm assuming the car did work before you started down this path, so it should work again.

A question: With the giubo removed, can you raise the driveshaft into position behind the front yoke on the output of the driveshaft, with the rear yoke not on the spline? Does this work with the rear yoke on the spline but pushed all the way toward the rear, and with the giudo still removed? In other words, is the giubo the problem or the driveline itself as we're currently thinking?

You know, this might be easier by phone. Send me a PM if you want to chat over the phone at some point.

-Bryan

[tdskip]

PM sent.

I'm 90% sure it is the drive shaft, the guibo is new from one of our usual suppliers and looks the same as the one removed.

There were non-factory welds on both ends of the driveshaft so it is at a well regarded local shop to be shortened. I have them shortening it by 1.25 inches, which will give me clearance to mount the guibo and once mounted some amount of back/forth travel (not not a huge amount).

[tdskip]

First of all, I hope everybody is deep into a happy Friday evening at this point.

I wanted to just follow up and give people the courtesy of tying this off. I am happy to say with your help and encouragement I was able to get the car sorted out and actually spent some time driving it around today. It turns out there were multiple issues that needed to be addressed, the orientation of the motor rounds was a key thing that then allowed other good things to happen, without that I’d still be throwing tools around the garage.

The driveshaft was indeed too long, and my shortening it an inch and a quarter has allowed it to not only fit but it appears that all is well in terms of movement when the car is in motion.


I sincerely appreciate everyone’s help and Patients with me, I know it looks like I was making stuff up there for a bit!

[RRoller123]

That is excellent news!