Pain in the Tailshaft!

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go-fish

go-fish

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I recently installed a rebuilt 318 and 727 in my 76 D100 2wd SWB. The truck originally had a different 318/727. My issue started with the crossmember mount not lining up with the through bolt. It is too far forward by 1/2". Initially I was thinking the whole engine/trans needed to be shifted to the rear more. Looking at the distributor cap verifies that the engine is definitely in the right location so it must be the trans mount, right? The engine mounts are in the exact same location that the original was.

I bought this Korean trans mount from Rock Auto where there are no reviews. So I went to Summit to find a different brand and I saw they also carry the Korean (Anchor brand) mount with terrible reviews. Looking at the reviews confirms that these are terrible but I didn't read any reviews with my particular bolt hole location issue.

Marching on, I called my Dad and he is sending me the original mount that came off the truck. He took the original 318/727 out of state to where he lives. I will just put a new bushing in the mount.

Sooooo, continuing, while I wait for the mount in the mail I decided to put on the trans cooler lines. What do you know, the fittings are too far forward by 1/2" too! I had to make a little bend in the cooler line to get the flare nut to be in the right position for the fitting.

I am stumped. It just seems that the tailshaft is forward 1/2" due to the mount and cooler fittings both being forward. The trans was rebuilt and in a B-body so it is a long tailshaft. To my knowledge the truck tail is the same, other than the car version having the floor shifter mounting ears. The trucks takeout 727 did not have the floor shifter ears but this current one does but I have never heard of there being two different length "long" tailshafts.

Anyone have knowledge of this? Is it just coincidence that the lines are long and the Korean mount is of poor quality? Is there a 1/2" difference in truck and car "long tailshafts"?
 
Did you have the trans crossmember out? The trans mount is not centered (fore & aft) on the crossmember, and if the crossmember gets re-installed 180* out it does not line up to the trans mount. Found out the hard way piecing together a basket case D200...
BTW, does the driveshaft still fit correctly, or is it 1/2" short now, too?
 
Professor Fate said:
Did you have the trans crossmember out? The trans mount is not centered (fore & aft) on the crossmember, and if the crossmember gets re-installed 180* out it does not line up to the trans mount. Found out the hard way piecing together a basket case D200...
BTW, does the driveshaft still fit correctly, or is it 1/2" short now, too?
Click to expand...


I did take the crossmember out. That is a good point to consider.
I cleaned up the slip yoke while it was out so it's hard to tell where that line from the seal is (inside of the seal was clean and the pat that was out of the seal was grimey). I wire wheeled and painted it so I can't see the demarcation line anymore.
 
Have you considered that you may have installed the engine brackets on the wrong side of the lugs? That's about a half inch right there.....
The trans mount is in the right location, for any trans that the truck came with. If you move it, you will have driveshaft length issues.

The bracket should be bolted onto the rear side of the lugs, which will tug the engine forward.

I'm pretty sure engine brackets for cars are different from trucks.
 
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They are.
AJ/FormS said:
I'm pretty sure engine brackets for cars are different from trucks.
Click to expand...


That’s was my initial thought, “Maybe my engine mount tabs are on the front of the block ears.” They’re not and the distributor cap is as close as I want it to the firewall. So, the engine is definitely in the correct position.
Bad mount or maybe the crossmember needs to be flipped 180 degrees. However, it looks pretty darn symmetrical AND the trans cooler line was off by the same amount the mounts bolt hole is.
Hmm?
I really want to hear someone say, definitively, that all “long” tailshafts are the same length. AFAIK, the only variation in “long” tailshafts is some have floor shifter mounting tabs and some don’t. I have never seen different lengths of the “long” housings.
 
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All longtail shafts ARE the same length. Some mounts have longer elongations where they bolt to the tail housing. What about where the mount bolts to the frame? And isn't there a difference between 318 and 360 mounts? Also, if your mounts are very old, the rubber might be distorted.
 
I don't have the D200 anymore that I talked about above, but after watching your video I went over to my neighbor's house, who has a similar one, and took a look at his. There is a "lip" on the crossmember on one side, and not on the other. On his, the lip is to the rear- your vid shows yours to the front. Flipping it might be enough to make up the difference. As said above, make sure any slots or play in the mounting holes are biased towards the front- if it's only a half inch off it doesn't take a lot of play to get it moved around.
 
CudaFactHackJob said:
All longtail shafts ARE the same length. Some mounts have longer elongations where they bolt to the tail housing. What about where the mount bolts to the frame? And isn't there a difference between 318 and 360 mounts? Also, if your mounts are very old, the rubber might be distorted.
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Thanks for that info. These are the original metal engine mounts and new biscuits. The mounts are stamped LR and RR so they in the right configuration. Also, the original engine is a 318 and so is this rebuilt one.
 
You need a new flux capacitor. That'll do it every time.
 
I wish I had an answer for you, especially because the exact same thing happened to me. I bought a '79 stepside dirt cheap that had pretty much a brand new 318 in it. Cam, 4 bbl, headers, etc. 727 looked like it was done at the same time. I decided to swap engines with my '77 shortwide (both 2wd), also a 318, but getting pretty tired. Motor and 727 direct from the'77 into the '79, didn't change mounts or brackets... and the trans mount hole was at least 3/8" too far forward. Checked everything my buddy and I could think of, and finally gave up. IIRC i slotted the trans mount a little, and used a smaller diameter bolt between the mount and crossmember. Traded the stepside to him shortly thereafter, he's still running it that way.
 
fshd4it said:
I wish I had an answer for you, especially because the exact same thing happened to me. I bought a '79 stepside dirt cheap that had pretty much a brand new 318 in it. Cam, 4 bbl, headers, etc. 727 looked like it was done at the same time. I decided to swap engines with my '77 shortwide (both 2wd), also a 318, but getting pretty tired. Motor and 727 direct from the'77 into the '79, didn't change mounts or brackets... and the trans mount hole was at least 3/8" too far forward.
Click to expand...

Do you think the trans crossmember could have been rotated 180 degrees?

Here are some me things I am certain of, engine mounts bolted on correctly and in the correct engine crossmember holes, the “long” tailshafts are all the same length.

I’m highly suspicious of the trans crossmember at this point.
 
I highly doubt it, I left everything alone. And what makes it even stranger, the motor and trans from the '79 went into the '77 without a hitch.
 
The cooler lines don't enter the tail shaft but into the main case. That tells me that (if they are original to a truck) that the problem is a ways forward of the trans mount.
 
Yeah, it’s definitely something to figure out. I’ll have 3 days R&R when I get back home so I will be getting to the bottom of it. The motor mounts seem to be in the right place but I’ll double check everything.
 
I noticed that the the holes in the engine mounts, where the isolators mount to are NOT centered in the brackets. And I noticed that you have installed them in such a way as to push the engine rearwards.
It seems to me that they are each of them on the wrong side of the engine.
I know that you said they were marked, but are you aware that left means as from the driver's seat. From under the hood, left is the driver's side. That goes for all things Chrysler; T-bars, rear springs, valve covers etc; left is always driver's side.
Was this helpful, lol.
 
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