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Transmission Disassembly and Assembly

Sekred

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#1
What am doing?. Basically rebuilding my transmission because of a problem with second gear synchromesh, grinding when shifting into second gear.


Disassembly.

I removed the transmission from the vehicle and cleaned before stripping so I was starting with a clean work area.

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Outer case removal

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Reverse gear set removed and view of shift fork and detents

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Input and Output shaft bearing retainer plugs. Note the plates I had to make to stop the shafts spreading when I undid the plugs. Left hand and Right hand treads and very tight with factory Loc Tight.

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Gear Set removed

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Differential gear set and reverse gear set removed


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Removal of Output shaft bearing

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I had to destroy the Input shaft bearing to remove it, nothing unusual here

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Input and Output gearsets. This is as far as I can go, I simply do not have the tooling to dismantle these gear sets. Getting the bearings off is ok but the gears need to be pressed off and they are a tight interference fit so it is off to the transmission shop and I mean a dedicated trans shop that know what they are doing.


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When I get the gearsets back I will post more images of the assembly procedure.
 


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Sekred

Sekred

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Thread Starter #5
Transmission Assembly

So I got my gearsets back from the transmission shop and now I can assemble the transmission.
What was replaced, input and output shaft bearings including the needle rollers located inside the gearsets. Trust washers and all circlips. 1st/2nd gear synchro rings and hub. 3rd/4th synchro rings. All seals.

I did not replaced 5th/6th gear synchro rings, differential bearings or reverse gear bearing. This transmission is already fitted with a Quaife LSD and vehicle has traveled about 25,000 kms. The Quaife been fitted for around 15,000. There is absolutely no reason why I should be experiencing synchro problems, more about that later.


Prepared and cleaned housings for assembly. I will refer to the housings simple as front and rear.


Installed axle seals in the front and rear housings, I am using a 3/4 socket set. The reason being I have plenty of different sized diameters to choose from.


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Install what Ford calls a funnel, maybe it has something to do with lubrication for the bearing.

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Install output shaft bearing. I stuck the bearing in the freezer for a few hours. This gives me a slight advantage during installation. I supported the case on 3 pieces of soft timber because of the locating dowels, hard wood would of be better here and then drove the bearing in using a socket. The bearing needs to be installed straight and bottomed on the lip inside the case.

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Install the input shaft bearing using the same method, this bearing is a tighter interference fit and I would suggest supporting the housing directly under the bearing.

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Now I can start installing the gearsets.

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Lubricate the bearings and install the final drive gearset and differential. This is the part that is replaced when a LSD is fitted.

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Install the reverse gearset, you will need to lift and tilt the final drive to do this.

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Now I am ready to install the gearset. The input and output shafts plus the 1st/2nd and 3rd/4th, 5th/6th shift fork shafts must be install as a unit. I used the small metal tabs I made before to hold one end of the gearset to together and cable ties on the other end and cable ties on the shift fork shafts. Despite the fact that I needed to align 4 things at the same time installation proved easy. About the last thing to do now before I can assembly the cases is to install the reverse synchro hub with detents and shift fork/shaft. Hold the detents in with a little grease.

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Now the rear case is ready to install. I need lubricate the gearset, shift forks, shafts, bearings and synchro hubs and basically everything you can see. I need to use a dedicated Case Bond to seal the transmission cases. The front and rear cases Must be clean and bone dry, no oil residue from assembly. Use alcohol or something similar to wipe the case halves. You will also have to install the guide bolts (not shown here) as use per the assemble procedure in the Ford service manual which I used as a reference to assemble the transmission. The guide bolts are install in the bearing carriers for the input and output shafts. I also used the service manual for all bolt torques.

This is also where things went pair shaped and I would of like a few more images. The problem began when installing the rear case. Like a lot of things there are tricks to the procedure. The trick here is to line up 5 things at once. Input and output shafts, and the 3 shift fork shafts as you lower rear case onto the front case. Anyway I eventually got the cases to line but the problem was time. With the case bond install, there is only so much time stuffing around before it starts to set and go off.

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I left the input seal till last to avoid damaging it. I could not use a 3/4 drive socket to install it because it would not fit over the input shaft so I went to the hardware shop and found a thick piece of PVC pipe that did the trick. The PVC was a little bigger that the seal so to drive it in the last mm or so I use the old seal to make sure it was bottomed on the lip.

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About the last thing to do before refitting the transmission to the vehicle was to fit a new slave cylinder.

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And something I missed before, reverse outer synchro hub and detents.


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OP
Sekred

Sekred

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Thread Starter #7
Just now having a good look at the synchro hub for 1st/2nd gear and the synchronizer ring, particularly the one for 2nd gear. There is visually nothing wrong. No real wear what so ever which leads to the obvious question why I was getting the grinding noise when shifting.
It can only be the lubricate I was using. A lubricate that does not meet the Ford spec, Penrite Pro Gear 75W-85 full synthetic or it may have been 75W-90. I will take a guess and say either the viscosity was the problem or the additives were slowing the synchronizing action from working correctly.
I know there are plenty of people running non spec oils on this Forum like Motul and was wondering if anyone was having shifting problems?

Here are a few picks of the synchronizing rings for 2nd and 3rd gear.


3rd gear synchronizer ring.
The rings are steel with a brass alloy material bond to the surface. The small grooves you can see allow the oil to escape fast enough when you shift gear. 1st/2nd are a triple cone ring design, 3rd/4th/5th and 6th are a double cone ring design.


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1st gear synchronizer ring.

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koozy

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#8
I'm using Redline DCTF with no issues. Viscosity of the gear fluid may be a bit thicker than optimal for smooth engagement.
 


Quisp

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#9
I've heard of oils being to slippery and causing syncro's to not keep up.
 


Bluedrank

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#10
An admin should really rename this thread because it's too good to have a typo in the title. Very helpful information here.
 


OP
Sekred

Sekred

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Thread Starter #12
Crap, I didn't even see the "a" or double s. Actually going to the Optometrist on Monday.
 


Intuit

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#13
......... look at the synchro hub for 1st/2nd gear and the synchronizer ring, particularly the one for 2nd gear. There is visually nothing wrong. No real wear what so ever which leads to the obvious question why I was getting the grinding noise when shifting. ...................
Prior car had an adjustable length push-rod between the clutch pedal and firewall. Any time shifting changed, I would lengthen it by a turn or few; of the fine threads. The manual for that had specifications for clutch pedal engage height and free-play.
 


Intuit

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......... look at the synchro hub for 1st/2nd gear and the synchronizer ring, particularly the one for 2nd gear. There is visually nothing wrong. No real wear what so ever which leads to the obvious question why I was getting the grinding noise when shifting. ...................
[MENTION=3955]Quisp[/MENTION] posted this link in another gear-grinding thread. These are instructions for adjusting the clutch pedal link cable. It's likely that this is all that was required. It wasn't often, but would need to make very minor adjustments with a prior manual transmission. That car had hydraulics linking the clutch pedal, so an adjustable length rod between the pedal and firewall was used instead.

https://www.fiestastforum.com/forum...nual-Transmission-B6?highlight=Adjust+shifter
 


OP
Sekred

Sekred

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Thread Starter #15
[MENTION=3955]Quisp[/MENTION] posted this link in another gear-grinding thread. These are instructions for adjusting the clutch pedal link cable. It's likely that this is all that was required. It wasn't often, but would need to make very minor adjustments with a prior manual transmission. That car had hydraulics linking the clutch pedal, so an adjustable length rod between the pedal and firewall was used instead.

https://www.fiestastforum.com/forum...nual-Transmission-B6?highlight=Adjust+shifter
Exactly what are you indicating here. That link you posed refers to adjustment for the cable gear linkages, it has nothing to do with the clutch.
The clutch on the ST is hydraulic "self adjusting" for wear. When I say wear I mean wear of the friction plate and pressure plate which causes the angle of the diaphragm fingers to change when the clutch is disengaged basically. As this happens, the piston in the slave cylinder has to move to compensate.
If the clutch was dragging meaning it is not disengaging properly then you can have gear grinding problems.
My problem had nothing to do with the clutch or cable adjustment and to update things now, the transmission is shifting perfectly. I put it down to the wrong spec oil I was using. Penrite is a small niche Australian oil company, there make great oils but in this case it was a bad choice.
Maybe I could of just changed the brand of oil and fixed the problem?, unlikely because the grinding progressively increase over a period of about 3 months to the point it was grinding when I was shifting back. The synchronizing cones are porous to a degree meaning the oil ends up absorbed into the surface and once its in the friction material its hard to get it out. Anyway, that's what I tell myself and I can't prove otherwise.
 


Intuit

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#16
If you mis-time your release of the clutch pedal during a shift, you may inadvertently grind the gears. The reason this occurs is due to the engine and trans not being fully disengaged. If they're not fully disengaged then your synchronizers won't have an opportunity to perform their function. This is why people are instructed to FLOOR their clutch pedals between shifts; on non-sequential transmissions. Having a misadjusted linkage/cable, preventing full disengagement, is like not flooring your clutch pedal.
 


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#17
Did you install the transmission yourself once you finished with the gears and other stuff? Any tips for lining it up to get it back on the block? I ran into an issue where it just doesn't seem to want to line up and reseat.
 


OP
Sekred

Sekred

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Thread Starter #18
There is no real trick to getting it back in. Just make sure it is square to the engine, top, bottom and the sides. You may need to rotate the input shaft so the spline goes into the friction plate. Use a little force on the back on the trans push it in, not too much or you can damage the friction plate. A tiny amount of high temp grease on spline will reduce the friction.
 


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