Restoring GPW 14518

Feb, 1942 - GPW1 thru end of first contract, April, 1942 - GPW15000 NO EBAY or COMMERCIAL SALES.
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Re: Restoring GPW 14518

Post by 17thAirborne » Fri Sep 04, 2020 10:53 am

With everything in place and torqued down I compared the slop between the two blocking rings and made sure they would freely rotate a few degrees on their respective cones. They do rotate, the two shafts will rotate independently when in neutral, but there is a difference between the spacing of the rings.
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The front ring has a good bit of clearance.
front ring clearance.png
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The rear ring is very tight and will barely move fore and aft, but it does rotate.

rear ring tight.png
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)


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Re: Restoring GPW 14518

Post by 17thAirborne » Fri Sep 04, 2020 11:09 am

Using a feeler gauge, I can measure between the clutch hub and the blocking ring. I get 0.044" in front and 0.017" at the rear. A difference of 0.027".

From what I understand, the rear clearance is fixed and cannot change. What you are attempting to do is to adjust the slop in the front blocking ring so that it closely approximates the rear ring.. The front clearance can be decreaced by adding special shims, or increased by removing thickness of the spacer, or eliminating the oil baffle (which is not needed with sealed bearings) NOTE: If you copied or read this before the last change was locked in, you need to read it again. I had some errors in how I described adjust ment of the clearance.

RANT: SINCE WE ARE BLOCKED FROM MAKING CHANGES AFTER 2 HOURS, OUR ERRORS ARE ENSHRINED FOREVER AND WILL LEAD MANY ASTRAY.
clutch hub to blocking ring clearance.jpg
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Sat Sep 05, 2020 7:08 am

Goal for the day: Add shims on the mainshaft to equalize slop between two blocking rings.

Outcome: Adding 0.025" of shims made it so tight that neither blocking ring would rotate freely and there was no slop in either ring. The two shafts would not spin freely in neutral indicating too aggressive use of shims.

Decision: I consulted with my friend who knows T84s. We had a long conversation and he believes that the lask of slop in the rear or 2nd gear blocking ring is troubling. I measured its length of the 2nd gear and found it to be 1.352" The tolerance should be between 1.340" and 1.353". That places this in the almost too long category and has made the blocking ring really tight. It's a CROWN gear. The original, which is pitted is 1.342". I'm going to call the vendor and see what he says.

Here are the shims from Ron's kit.
main shaft shims.JPG
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Here they are fitted onto the shaft before assembling everything together as before, yet again.
Shim Configuration.JPG
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Just a note I found it easier to lay the two cases as shown to get the rear bearing to "slide" into the transfer case bearing recess. I used some slight taps with a rubber mallet to coax the transmission down. Just be careful not to introduce side loads as the bearing will enter the recess off angle and make it difficult.
Mating the cases.JPG
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Sat Sep 05, 2020 10:35 am

Here are the measurements between the OEM gear that I took from the transmission and the Crown gear purchased. The book specs for the overall part length are 1.340" - 1.353"
Note the forum deletes empty spaces so its hard to line up columns unless you import an excell table :?

Dim OEM Crown Description +/_
A 1.347" 1.353" Overall Length .006"
B 0.088" 0.075" Shoulder .013"
C 0.240" 0.252" 2nd gear .012"
D 0.715" 0.720" Gear and mesh .017"
E 0.305" 0.305" Cone .000"
Total 1.348" 1.352" A=B+C+D+E +/- .001" due to additive measurement errors

The crown gear has significant differences from the OEM gear, and the overall added length, although within specs, causes the cone to push the blocking ring tightly against the clutch hub. If the gear were shorter, I would gain some "slop" on the aft blocking ring.
2nd gear specs.png
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Sat Sep 05, 2020 10:45 am

Just another data point regarding the rear bearing.
The recess for the bearing on the back side of the transmission case is 0.188"
The recess for the bearing on the front of the transfer case is 0.619"
The gasket thickness is 0.020"

TOTAL .188+.619+.020= .827"

BEARING: 0.825" which leaves 0.001 on the front and rear of the bearing, or 0.002" on either side depending on which case it is bottomed out on. If you add gasket crush, there is no extra space. So....don't use thinner gaskets. It might not seal??
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Sun Sep 06, 2020 7:54 am

Notice in the table of measurements above, the numbers listed for C and D should be switched. Obviously, the larger number is for C, the gear, and the smaller number for the mesh teeth, D.

Alas, I cannot change my post.
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Fri Sep 11, 2020 3:29 pm

I was incorrect in the type of 2nd Gear I purchased. It is not a Crown, but a US made from PDJP. Refer to the post above regarding the measurement differences of the original and the new 2nd gear.

If the length of the gear was about 0.007 -0.009" shorter, I would end up with a bit more slop on the fore/aft movement of the rear blocking ring. When I installed my original 2nd gear (pitted and worn) just to test this assumption, the slop increased by about that amount, as it is 0.007" shorter than the new 2nd gear. Hope my explanation makes it a bit more easy for you to visualize what I am thinking here.

My task is to match the slight slop of the front blocking ring to that of the rear one. The rear blocking ring slop is fixed because the components on the front part of the main shaft, forward of the splined shoulder are fixed between the shoulder and the small snap ring.

In a post above I used 0.025" of shims in an effort to reduce the front blocking ring slop and found that it made things too tight. On this attempt, I used 0.010", or one of the thick shims from RFJP, and tested everything. It did improve things quite a bit. The slop between front and rear blocking rings are not exactly the same, but I think it will be sufficient. The video below demonstrates the verification of the following:

1. When in neutral, both shafts turn independently of one another ie. no binding.
2. The gap in front of and behind the clutch hub shifting plates GPW 7116 (dogs) are fairly consistent with slight variations
3. When alternately in 2nd and 3rd gear, the blocking rings are free to rotate and the "slop", fore and aft, is approximately the same, just a bit tighter on the rear ring.
4. All gears (Rev, Lo, 2nd and 3rd) engage properly and allow the transfer of rotation to the output shaft in the appropriate manner.

With this test completed, I can now press on my aft transmission bearing, and do a final assembly of the transmission. I will just confer with my Subject Matter Expert before doing so. He'll review the video for me.

Here is the vid:

https://www.youtube.com/watch?v=X-PUEx2ibwg
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Fri Sep 11, 2020 3:49 pm

After a review with my friend, I am going to exchange the 0.010" shim for a 0.005" shim and give it another try.
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Fri Sep 11, 2020 5:22 pm

I am cured.....of my propensity to only want to assemble a thing ONCE. I have re-assembled this T84 7 times now and have two more to go. One to test the 0.005" shim and the final assembly. I now see the efficacy of doing things over and over to tweek things juuuust right.
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Sun Sep 13, 2020 12:29 pm

Assembling for the 8th time I was thinking, " Man I am getting good at putting this thing together really fast without referring to anything." Just as I get ready to torque the main shaft output gear nut down real tight, I look in the parts tray and see something shiny....the 3rd gear blocking ring :oops: So I' do it all over again. :lol:

Anyway, with the 0.005" shim in place of the tenner, the slop on the 3rd gear blocking ring is no longer so tight, but it's a bit greater than the 2nd BR. Undershot, now slightly overshot, but they really are pretty close. NOW I believe I'll call it ready for final assembly

That is unless anyone sees anything else to do here? My internet data upload speed is not so great, so I'll get the vid posted tonight or tomorrow.
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Sun Sep 13, 2020 1:37 pm

Here is the last video of the slop. Had to hold the camera and move the rings around, so shorter than the last and a bit jittery.

https://www.youtube.com/watch?v=FBIcAVtstNk
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Tue Sep 15, 2020 11:21 am

The next phase will be the cleaning and inspection of the Transfer Case components. Here is the extract from the TM. Use the figures that I posted above for reference.


13. CLEANING, INSPECTION, AND REPAIR.

a. Cleaning. Clean all parts thoroughly in dry-cleaning solvent. Clean the bearings by rotating while immersed in dry-cleaning solvent until all trace of lubricant has been removed. Oil the bearings immediately to prevent corrosion of highly polished surfaces.

b. Inspection.

(1) Transfer Case Assembly (Fig. 27) Inspect the transfer case housing for cracks or damage of any kind. Inspect the bottom and rear cover for bent or damaged condition. Replace the gaskets on the bottom and rear covers.

(2) Front Output Shaft Bearing Assembly (fig 21)

(a) Front Output Shaft Bearing Cap Housing (fig. 20). Replace the front bearing cap if it is cracked or damaged. Shifter shaft and output shaft oil seals must be replaced. (subpara. c. below)

(b) Front Wheel Drive Shifter Shaft and Fork (fig. 21) Replace the Front Wheel drive shifter shaft if bent or damaged. Replace the fork if it has stripped set screw threads, if it is cracked or has bent forks.

(c)Crutch Shaft and Gear (fig. 21)Replace the clutch shaft if the splines or gear teeth are chipped or worn, if the gear has any teeth missing. Check the diameter of the pilot end of the shaft. If the diameter is less than 0.625" replace the clutch shaft. Replace if the clutch gear if it is worn or has any broken teeth.

(d) Output Shaft Bearing (fig. 21) Ball bearings with loose or discolored balls or with pitted or cracked races must be replaced.

(3) INTERMEDIATE GEAR ASSEMBLY (fig. 25). ‘Replace the intermediate gear if excessively worn, or if any teeth are damaged Check
the thickness of the thrust washers. If the thrust washers are less than 0.093" in thickness, replace them. Check the diameter of the intermediate gear shaft If the diameter is less than 0.750", replace the intermediate gear shaft. Replace the roller bearing, if the rollers are scored or have flat spots.

(4) REAR OUTPUT SHAFT BEARING (Fig. 26) Replace the output shaft bearing cap if cracked or damaged. Replace the speedometer drive gear if it is worn or has damaged teeth. Replace the oil seal in the output shaft bearing cap housing (subpar. c, below). Replace the brake drum if it is worn or bent Replace the universal joint rear flange; if the splines are worn, Replace the dust shield on the flange if bent.

(5) OUTPUT SHAFT ASSEMBLY (fig. 24). Replace the output shaft if the splines are worn. Small nicks can be removed by honing
and then polishing with a fine stone, Measure the inside diameter of the bushing in the output shaft. If it is greater than 0.627", replace the output shaft Replace the output shaft gear if it is worn or has any damaged teeth. Replace the sliding gear, if it is worn or has damaged teeth. Measure the thickness of the thrust washer. If the thrust washer thickness is less than 0.103", replace it. Replace the roller bearings if they are scored or have flat spots, or if the races are nicked or cracked.

(6) UNDER DRIVE SHIFTER FORK ASSEMBLY (fig. 24). Check the fork for stripped set screw threads, cracked or bent forks. Replace if in any of these conditions. Replace the under drive shifter shaft if it is bent.

(7) SHIFT LEVER ASSEMBLY (fig. 29). Replace the shift levers if found bent or damaged. Replace the shift lever spring if bent or cracked. Measure the diameter of the shift lever pivot pin. If the diameter is less than 0.500", replace the pivot pin.

c. Output Shaft Bearing Cap Oil Seal Replacement (fig. 20). Drive the old oil seal out of the output shaft bearing cap housing, using
a suitable driver. Drive the oil seals out, working from the inside of the cap housing. To install a new oil seal, use a driver the size of the oil seal and drive the new seal in the output shaft bearing cap housing.
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Tue Sep 15, 2020 11:33 am

TM:
13. CLEANING, INSPECTION, AND REPAIR.

a. Cleaning. Clean all parts thoroughly in dry-cleaning solvent. Clean the bearings by rotating while immersed in dry-cleaning solvent until all trace of lubricant has been removed. Oil the bearings immediately to prevent corrosion of highly polished surfaces.

b. Inspection.

(1) Transfer Case Assembly (Fig. 27) Inspect the transfer case housing for cracks or damage of any kind. Inspect the bottom and rear cover for bent or damaged condition. Replace the gaskets on the bottom and rear covers.


OZ:

Rather than cleaning everything at first I will clean each part as I do the inspection. Nothing to post here.

I have already cleaned inspected and primed my transfer case as shown above, as I used it to properly set my blocking ring slop. I would advise everyone do so. It seemed to make it easier than using clamps, which will not give a proper indication anyway. I also will order another gasket set as I used the first one for continually checking the slop as I added and removed shims.
Transfer case cleaned.JPG
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Tue Sep 15, 2020 11:38 am

TM:

(2) Front Output Shaft Bearing Assembly (fig 21)

(a) Front Output Shaft Bearing Cap Housing (fig. 20). Replace the front bearing cap if it is cracked or damaged. Shifter shaft and output shaft oil seals must be replaced. (subpara. c. below)


OZ: Sometimes we are a dumb-ass. :oops: Earlier when removing the front output seal on the front bearing cap, I cracked the bearing retainer lip from the inside. It cannot be repaired, so I'm in the market for a new one. The part number is GPW 7774.
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)

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Re: Restoring GPW 14518

Post by 17thAirborne » Tue Sep 15, 2020 11:57 am

TM:

(b) Front Wheel Drive Shifter Shaft and Fork (fig. 21) Replace the Front Wheel drive shifter shaft if bent or damaged. Replace the fork if it has stripped set screw threads, if it is cracked or has bent forks.

OZ: These two parts are in beautiful shape. Just a bit of patina, no damage or cracks. I think I will leave the safety wire attached as a testament to the beauty of the original work. Its on nice and tight and I can't bear to cut it off. 75 years old and still looking great. I am pleased to see the Script F marks.
shifter fork 7712 and shaft 7787.JPG
Oz

Feb 43 GPW 98532 USA 20206257
Oct 70 Land Rover Series 2a 25334079G NZ16GF36
http://gpw.castraponere.com/ (My Restoration Page)


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