Engine to 727trans maximum misalignment
Printed From: TheAMCForum.com
Category: The Garage
Forum Name: Transmission & Drivetrain
Forum Description: If it's between the engine and wheels, it goes here
URL: https://theamcforum.com/forum/forum_posts.asp?TID=116327
Printed Date: Apr/23/2024 at 3:03pm
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Topic: Engine to 727trans maximum misalignment
Posted By: Em390
Subject: Engine to 727trans maximum misalignment
Date Posted: Jul/23/2022 at 1:20pm
| How much can the engine and transmission be misaligned? 727 torqueflite to 401 |
Replies:
Posted By: 304-dude
Date Posted: Jul/23/2022 at 1:49pm
I am not getting the question. If properly installed, there is no misalignment issues. Are you talking about torque converter or trans mount height? ------------- 71 Javelin SST body 390 69 crank, 70 block & heads NASCAR SB2 rods & pistons 78 Jeep TH400 w/ 2.76 Low 50/50 Ford-AMC Suspension 79 F150 rear & 8.8 axles Ford Racing 3.25 gears & 9" /w Detroit locker |
Em390 wrote:Posted By: farna
Date Posted: Jul/31/2022 at 2:19pm
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The engine to transmission centerline can only be off 0.003" or so -- hardly any at all! Much more and you'll have vibrations and other issues. That's why there are alignment dowels on the engine for the bell housing and the trans is a snug fit in the hole in the back of the bell (on older autos and manuals with separate trans/bell). I had an engine that had been in a wreck and the alignment dowels sheared off. Aligning the (manual) trans with just the bolts wasn't good enough, after about 300 miles the center of the clutch ripped out even though it only had some vibration and chattering the first 50-100 miles, then seemed to "wear in". I doubt a torque converter would last that long! replacing the dowels didn't help much, got about 700-800 miles out of it! When it started to make a little noise at about the 400-500 mark, I started looking for another block. Luckily this was a common 4.0L block. Hard to find a good used one in 98 when I started, but by 2000 they were more plentiful in salvage yards because the 4.0L powered Jeeps were so popular and by then 10 year old models were nearing their end of life -- not because the engines were bad! ------------- Frank Swygert |
Posted By: 6PakBee
Date Posted: Jul/31/2022 at 7:28pm
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You can dial in a TF case the same way you can dial in a bell housing using the pump bore. ------------- Roger Gazur 1969 'B' Scheme SC/Rambler 1970 RWB 4-spd Machine 1970 Sonic Silver auto AMX All project cars. Forum Cockroach |
Posted By: Trader
Date Posted: Aug/01/2022 at 8:01am
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Have seen them off by as much as 0.015" on Fords. They would not make these if it was not a common issue: https://www.summitracing.com/parts/sum-192008?seid=srese1&gclid=Cj0KCQjw852XBhC6ARIsAJsFPN1J4UIWI2bbbU2O5B3owX1YiB-5oYU2mgclpCqekDd_iBbUMhXFIGcaAi06EALw_wcB" rel="nofollow - https://www.summitracing.com/parts/sum-192008?seid=srese1&gclid=Cj0KCQjw852XBhC6ARIsAJsFPN1J4UIWI2bbbU2O5B3owX1YiB-5oYU2mgclpCqekDd_iBbUMhXFIGcaAi06EALw_wcB Never had an AMC off by more then 0.005".
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Posted By: Ken_Parkman
Date Posted: Aug/01/2022 at 9:29pm
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I bought an aftermarket adapter for a powerglide to AMC years ago. The runout was something like .100" (which contributed to my hatred of adapters) which obviously would have destroyed the glide. I got it to about .008" (IIRC) which seemed to be mostly OK, but I didn't like it. I would break a TH400 style flexplate about every 100 passes, but I really think that was mostly the plate simply not strong enough. Then I got an Ultrabell which was just aligned by bolts when they came out and it was about .020". In a rush and thought it might be OK, took the pump out of the glide. Figured out how to align it, it's .001" now. Also why I am a freak on proper alignment.
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Posted By: DragRacingSpirit
Date Posted: Aug/03/2022 at 2:07pm
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I guess I have been lucky.....knock on wood. I have never aligned an auto tranny in any of my cars. That includes 400 turbo with ultrabell, powerglide with ultrabell, and stocker 400 and 727 transmissions. Never had a problem. You would know it quick when the front pump bushing and seal are out.......transmission fluid would be gushing I would think ? ------------- Best 1/4 mile 8.99, 1/8 mile 5.71, 60 foot 1.27, no power adders |
Posted By: Ken_Parkman
Date Posted: Aug/04/2022 at 9:22pm
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It took a while to damage the pump. I found the bushing and pump gears scored on winter maintenance, so it was not a total disaster. But it made me make it straight by slightly enlarging the ultrabell bolt holes, spending a huge amount of time getting a runout on the stator support, then tapping it around to get zero, tighten the bolts, then drill the properly aligned ultrabell and pump housing for dowel pins. Now it is repeatably straight on assembly. I usually don't worry about proper factory assembly. The OEMs have proper engineering and quality control; they have to or they would be bankrupt. (oh yeah AMC is no longer around! But I don't think because of that) But I have a healthy distrust of aftermarket Engineering and quality control or lack thereof! In Engineering terms bolts don't line anything up.
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Posted By: DragRacingSpirit
Date Posted: Aug/05/2022 at 3:29pm
Great idea! ------------- Best 1/4 mile 8.99, 1/8 mile 5.71, 60 foot 1.27, no power adders |
Posted By: Steve_P
Date Posted: Aug/05/2022 at 10:38pm
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OE parts you install on the block's dowels and that's it IMO. You can check it if you want to, but.... Anything aftermarket you need to check with a dial indicator. The problem is that I don't think there are any offset dowels made for AMC. Years ago I had some made for a Lakewood bellhousing that was ~.010 out of center....
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Posted By: Coloradoamx
Date Posted: Aug/06/2022 at 12:31pm
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Offset Dowel Pins are available for AMC in .007, -014, .021 https://www.jegs.com/i/Silver-Sport-Transmissions/833/BHJ-01007/10002/-1" rel="nofollow - https://www.jegs.com/i/Silver-Sport-Transmissions/833/BHJ-01007/10002/-1 |
Posted By: Trader
Date Posted: Aug/06/2022 at 1:28pm
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Nice find. Also most AMC's I have found are offset vertically. It's easier to fix this with one straight dowel and one offset. There will be a minor angle offset doing this, but if you switch the offset dowel from one side to the other you can usually find the best position and get it within 0.002" which is fine for any street engine, PO.
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Posted By: Coloradoamx
Date Posted: Aug/06/2022 at 3:31pm
| It becomes more of an issue if the block has been line bored in the past. Especially troublesome with the newer manual transmissions. |