Technical 1978 124 Project

[smahaley]

Sometimes you can swap some of your existing shims around to reduce the number of shims you have to buy.

One way, having measured your valve clearances, is to remove all the shims, measure them and see if you can indeed swap some around. The cam lobes should be fine operating the valve buckets (followers) with the shims removed, when just turning over the engine manually using a wrench.

However, a really smart person would probably have measured each shim before assembling the head and then he'd know which size shim was installed on each valve and could determine if any could be swapped around before he removed them....

(lmao) a really smart person…. I noted TWO of the shim numbers before installing and then just lost my way, so….

I’ll pull them each and note and see about swapping….

 

[smahaley]

Ok: I will have to buy the little tool to hold the buckets / valves down. I’ve tried some things I have and nothing works. Meanwhile, I’m not sure what this is about:

That looks like a crankshaft pulley (although mine has 3 grooves to accomodate a deleted air pump assembly) and I have no memory of there having been an o-ring.

I do have a rubber o-ring that came in my gasket kit - this just seems weird to me (deeply scientific and often incorrect gut feeling).

 

[Slotman]

I had my crank pulley off 2 months ago and don't recall any "o" ring either..

 

[smahaley]

To remount the flywheel I had to build a box stand for the motor so I could take off the engine stand.
Question: torque spec for flywheel bolts is listed in Haynes as 58 ft lb, while in Pininfarina shop manual at 105 ft lb.

I’m thinking 105? Wildly different numbers…

 

[Slotman]

Could it be there's different size bolts for different years?
Just for fun I asked A.I. and it came back with 65 to 75 "typically " for a 78 further confusing things...to really mess things up in will go check my Chilton manual and add it to this post

 

[smahaley]

Could it be there's different size bolts for different years?
Just for fun I asked A.I. and it came back with 65 to 75 "typically " for a 78 further confusing things...to really mess things up in will go check my Chilton manual and add it to this post

Yeah I saw a post somewhere talking about 10 mm bolts taking something like 40 and 12 mm taking 60 or so - and these 6 bolts are 19mm! So I went toward 105… seemed like the correct setting and is aligned with Pininfarina…

The other fun bit on this step is that my friend removed the pressure plate without marking it. SO. I’ve looked all over it for a mark but, none seen - so I have just put it on in one of the 3 possible orientations… (shrugging my shoulders).

 

[Slotman]

Chiltons comes in at 61lbs for flywheel to crank bolts for a 78., on the pressure plate you have a clutch pilot tool for alignment correct?
Opps, see the pilot tool!

 

[smahaley]

So…. I did something dumb and these pins fell out of my transmission. I’ve read Haynes and Pininfarina and they don’t give specifics on exactly where these two “detente dowels” should reside. YouTube hasn’t helped either…

I’ve taken the 5th/reverse shift arm out (first photo) and stopped to see if the wise folk here could give me some pointers…

I have the plate off the side that carries (with 3 springs) the 3 detente balls. These pins though??

 

[Twink80]

View attachment 469644
View attachment 469645
So…. I did something dumb and these pins fell out of my transmission. I’ve read Haynes and Pininfarina and they don’t give specifics on exactly where these two “detente dowels” should reside. YouTube hasn’t helped either…

I’ve taken the 5th/reverse shift arm out (first photo) and stopped to see if the wise folk here could give me some pointers…

I have the plate off the side that carries (with 3 springs) the 3 detente balls. These pins though??

My guess would be somewhere along the gear selector shafts are some machined notches The detents are spring loaded and locate in the notches on the selector shafts

But I’m not sure if thebits you are holding are the selector shafts But I’m detents.
Gearbox rebuilds way more complicated than an engine and less frequently done so not so much info unfortunately

 

[smahaley]

My guess would be somewhere along the gear selector shafts are some machined notches The detents are spring loaded and locate in the notches on the selector shafts

But I’m not sure if thebits you are holding are the selector shafts But I’m detents.
Gearbox rebuilds way more complicated than an engine and less frequently done so not so much info unfortunately

Thanks @Twink80 - I just wonder why they fell out? I had only taken the bottom pan off and the top gear selector (extension) housing. Hmmm.... I'm trying to avoid taking more things apart...

 

[Twink80]

Thanks @Twink80 - I just wonder why they fell out? I had only taken the bottom pan off and the top gear selector (extension) housing. Hmmm.... I'm trying to avoid taking more things apart...

Tbh its difficult to tell what the parts are from the photo, they could also be dowels or a needle roller. I haven’t taken a gearbox to bits for 30yrs so don’t recognise the parts
Its possible that if they are detents they could be held in place by the cover?
The larger one with a groove has quite a specific shape so might make it easier to identify?

 

[smahaley]

Thanks yes - I have yet to find a decent diagram. And no they didn’t fall out of the detent bearing holder (with the cover and 3 springs) as the cover was on and springs / bearings in place after those 2 nuggets appeared. I’ll keep investigating, but may have to remove gears…

Update: Just found this (https://autoricambi.us/transmission-detent-bean---1st-2nd) and this video () so now I'm on the path to discovering where these things go....

 

[smahaley]

Detent beans - video:

Thanks yes - I have yet to find a decent diagram. And no they didn’t fall out of the detent bearing holder (with the cover and 3 springs) as the cover was on and springs / bearings in place after those 2 nuggets appeared. I’ll keep investigating, but may have to remove gears…

Update: Just found this (https://autoricambi.us/transmission-detent-bean---1st-2nd) and this video () so now I'm on the path to discovering where these things go....

 

[smahaley]

Tbh its difficult to tell what the parts are from the photo, they could also be dowels or a needle roller. I haven’t taken a gearbox to bits for 30yrs so don’t recognise the parts
Its possible that if they are detents they could be held in place by the cover?
The larger one with a groove has quite a specific shape so might make it easier to identify?

So…. I found a 2010 thread on another forum about this AND another detent dowel appeared yesterday! I was laughing after I put things together a 3rd time and dowels just fell out from somewhere.
That’s when I realized I had taken out the sensor that is at the end of the dowel tunnel (I’ll call it). That sensor I believe is connected to the EGR or something - and was a feature of Calif smog fighter cars. Therefore that FIFTH dowel never shows up in the repair manual. So to summarize:
1) they are detent dowels and all ride in the same tunnel that transects the entrances for the 3 shift arms
2) shift arm 1-2 and shift arm 3-4 both have narrow / smaller dowels that reside within them, aligned with the other dowels in the tunnel
3) (this is where I need to test) 1 long fat dowel goes in first and rides on top of the sensor. Shift arm 1-2 goes in. Another long fat dowel goes in. Shift arm 3-4 goes in. Two balls with springs go in to interface with shift arms 1-2 and 3-4. The short fat dowel goes in. Then shift arm 5-R goes in. Last ball and spring goes in.

If the above holds true I’ll write it up and post here - as a guide.

I’ve nearly lost my mind on this. lol

 

[Slotman]

Man, my brain is smoking...good job!
Even pollution junk on a manual tranny,
My 79 is a California smog car (before it was neutered) but mine is an automatic...makes me wonder what's on mine