Flexplate Replacement Parts (+ tangential component replacements)

[Zeb]

*Been lurking for a couple years, but finally have a question that I can't find the answer to by just reading:

I'm prepping to replace the flywheel on my M1008 (gonna put a Pioneer FRA-142 from Autozone on it). Been a long time since I've opened up a transmission housing, and this'll be the first time on a CUCV. Plan on using the strategies outlined in this old SS thread. I'm self-taught and extremely novice when it comes to mechanics...so please excuse my ignorance... but despite searching and reading up on this site I'm having trouble confidently compiling a list of all the parts/pieces/tools I'll need to get this done right and quickly. Typically I just tear into a project and find out along the way that I only have about half of what I needed, but I recently totaled my car and now the M1008 is my daily driver, so this will need to be done within a weekend. So far, this is what I've got listed to order/purchase before starting:

• Flexplate
• Bolt kit
• Some blue Threadlocker
• Guage to make sure I've got the correct gap spacing between starter and flexplate teeth
• Rebuilt direct drive starter from Hillbilly Wizard (don't want any damage on the current starter teeth to pay it forward to the new flexplate)

Is there anything else I'll need to get this done? Will there be gaskets that I should replace while I'm in there? Should I go ahead and order some shims just in case the starter & flexplate don't line up quite right?

Thanks in advance for any help, and please excuse my ignorance if any of my questions have painfully obvious answers to some of you more experienced folks out there.

 

[cucvrus]

I think you are ready to go. I completed this job on a lift and on the ground. Either way you don't need to remove the transmission to do the job. Just 4" long 3/8" bolts and slide it all back and replace everything. I changed over a 100 of them. The hardest part I encountered over the years was the stripped and twisted cooler lines. Some I could not get out because they were stripped and had rubber hoses installed. I have since changed my method. If I encounter stripped hacked up cooler lines that are spliced, I add hydraulic rubber lines and run them up over top of the transmission. That is a bit costly, but it saved me from getting them caught when off road and snow plowing. The next thing that can be a bear is the fill tube. Replace the shot glass shaped grommet that goes in the transmission and try, and wire tie the fill tube up in the general area where it is supposed to be. It can be a challenge and I have encountered more than 1 that was never put back in place with the tab bolted to the bell housing. Good Luck. Report back and Happy Holidays.

 

[Sharecropper]

I think you are ready to go. I completed this job on a lift and on the ground. Either way you don't need to remove the transmission to do the job. Just 4" long 3/8" bolts and slide it all back and replace everything. I changed over a 100 of them. The hardest part I encountered over the years was the stripped and twisted cooler lines. Some I could not get out because they were stripped and had rubber hoses installed. I have since changed my method. If I encounter stripped hacked up cooler lines that are spliced, I add hydraulic rubber lines and run them up over top of the transmission. That is a bit costly, but it saved me from getting them caught when off road and snow plowing. The next thing that can be a bear is the fill tube. Replace the shot glass shaped grommet that goes in the transmission and try, and wire tie the fill tube up in the general area where it is supposed to be. It can be a challenge and I have encountered more than 1 that was never put back in place with the tab bolted to the bell housing. Good Luck. Report back and Happy Holidays.

Hey Rick - The bolts that attach the transmission to the engine are M10-1.5, not 3/8". A 3/8 bolt will thread into the hole approximately 1/4" before it becomes thread-bound. In my opinion a 1/4" of thread is dangerously close to being too short to support the weight of the transmission when slid backwards. Yeah I know you have done this 100's of times and a 3/8 bolt must have worked, so maybe it does work. But just wanted to clarify the correct thread size for those bolts. Sorry if I stepped on your toes. Mike

 

[cucvrus]

Hey Rick - The bolts that attach the transmission to the engine are M10-1.5, not 3/8". A 3/8 bolt will thread into the hole approximately 1/4" before it becomes thread-bound. In my opinion a 1/4" of thread is dangerously close to being too short to support the weight of the transmission when slid backwards. Yeah I know you have done this 100's of times and a 3/8 bolt must have worked, so maybe it does work. But just wanted to clarify the correct thread size for those bolts. Sorry if I stepped on your toes. Mike

No, I am sorry. The bolts that bolt a bellhousing to the block of the stock 6.2 are 3/8 - 16 SAE. That may not be the case on that fancy new engine you have but I am 100% positive I have used a 9/16" swivel impact socket since the 70's to remove any transmissions in GM truck up to the 1991 R & V models. After that I am not sure where the change took place. Also, the transmission adapter to transfer case bolts are 3/8- 16 and I think the other side spacer to transmission are metric and then you have metric and standard converter bolts with 11/16" flex plate to crank bolts and 5/8" front drive shaft to transfer case flange and you use the entire toolbox to disassemble and reassemble a CUCV. Check me out. I wouldn't guess anything. But doubt will always be there. Happy Holidays. Quick question. What size is the pintle hook nut? Off the top of my head, I say 1 5/8"

 

[Sharecropper]

No, I am sorry. The bolts that bolt a bellhousing to the block of the stock 6.2 are 3/8 - 16 SAE. That may not be the case on that fancy new engine you have but I am 100% positive I have used a 9/16" swivel impact socket since the 70's to remove any transmissions in GM truck up to the 1991 R & V models. After that I am not sure where the change took place. Also, the transmission adapter to transfer case bolts are 3/8- 16 and I think the other side spacer to transmission are metric and then you have metric and standard converter bolts with 11/16" flex plate to crank bolts and 5/8" front drive shaft to transfer case flange and you use the entire toolbox to disassemble and reassemble a CUCV. Check me out. I wouldn't guess anything. But doubt will always be there. Happy Holidays. Quick question. What size is the pintle hook nut? Off the top of my head, I say 1 5/8"

Rick you are probably right. The transmission-to-block bolts on my fancy new P400 engine are indeed M10-1.5. Maybe the older 6.2's were 3/8-16. Were the earlier 6.2 engines metric or SAE?

 

[cucvrus]

The OEM 6.2 diesels and gas engines were SAE standard all the way up to the old cab V/R cab chassis, Suburban and K5 Jimmy and Blazer models. GM used standard body bolts and metric and standard power train bolts all the way up to the new 1988 cab. That was a very confusing era when it came to fasteners. I can remember when the fasteners were blue when they were metric. Strange stuff, I pulled engines from 1999 Dodge trucks that still had standard engine fasteners. My 1994 F250 with 7.3 had all metric body and transmission with all standard engine fasteners. It was the 7.3 NA engine. Good engine for a boat anchor. I like modern engines myself. people say you can't work on them. To me that is great. I really have not had to. A few trucks we have, have 200 K of hard use and still keep going day in and day out. 2015 GMC with 236K and never had anything but oil changed and spark plugs. No jab about the fancy engine but that is the space shuttle engine compared to the 6.2 diesel. Happy Holidays. And I still have the same 9/16" swivel socket I used back in the 70's. I am getting old. Oh Well.

 

[Sharecropper]

No jab about the fancy engine but that is the space shuttle engine compared to the 6.2 diesel.

Rick - Are you saying my P400 could work in the space shuttle? Dayum, I better put in a bigger transmission.

 

[MarcusOReallyus]

The only thing worse than manufacturers still using SAE is manufacturers MIXING metric and SAE!!!

Roman numerals, inches, feet, furlongs, pecks, cubits, and bushels ALL need to be thrown onto the ash heap of history!


That said, this may be just a question of terminology, but I don't think you need to open up the transmission housing to change the flex plate. It's inside the bell housing, which is not really the same as the transmission housing.

Been a long time since I've opened up a transmission housing,

 

[Zeb]

I think you are ready to go. I completed this job on a lift and on the ground. Either way you don't need to remove the transmission to do the job. Just 4" long 3/8" bolts and slide it all back and replace everything. I changed over a 100 of them.

Thanks! What size bolts to have on hand was actually my next question. I appreciate you specifying that.

...may be just a question of terminology, but I don't think you need to open up the transmission housing to change the flex plate. It's inside the bell housing, which is not really the same as the transmission housing.

Yes, that was an error in terminology on my part. Thanks for pointing that out though. On that note, will the bell housing cover have a gasket on it that I should have an extra on hand in case it needs replacing?

 

[ezgn]

*Been lurking for a couple years, but finally have a question that I can't find the answer to by just reading:

I'm prepping to replace the flywheel on my M1008 (gonna put a Pioneer FRA-142 from Autozone on it). Been a long time since I've opened up a transmission housing, and this'll be the first time on a CUCV. Plan on using the strategies outlined in this old SS thread. I'm self-taught and extremely novice when it comes to mechanics...so please excuse my ignorance... but despite searching and reading up on this site I'm having trouble confidently compiling a list of all the parts/pieces/tools I'll need to get this done right and quickly. Typically I just tear into a project and find out along the way that I only have about half of what I needed, but I recently totaled my car and now the M1008 is my daily driver, so this will need to be done within a weekend. So far, this is what I've got listed to order/purchase before starting:

• Flexplate
• Bolt kit
• Some blue Threadlocker
• Guage to make sure I've got the correct gap spacing between starter and flexplate teeth
• Rebuilt direct drive starter from Hillbilly Wizard (don't want any damage on the current starter teeth to pay it forward to the new flexplate)

Is there anything else I'll need to get this done? Will there be gaskets that I should replace while I'm in there? Should I go ahead and order some shims just in case the starter & flexplate don't line up quite right?

Thanks in advance for any help, and please excuse my ignorance if any of my questions have painfully obvious answers to some of you more experienced folks out there.

I'm thinking you have the wrong flex plate and bolt kit. Sorry my bad I punched in the wrong flex plate number. Summit shows FRA-142 FLEX PLATE fitting a 1991 Chevrolet. Amazon shows the correct one with the same number.

 

[cucvrus]

No gasket. Just take your time and put everything back the way it belongs. No short cuts or half fast tricks. Good Luck. I will be here waiting for a report. Have a question? Please ask no question is bad except the ones you don't ask and break something. Doing it right the first time is the only way.

 

[Zeb]

I'm thinking you have the wrong flex plate and bolt kit. Sorry my bad I punched in the wrong flex plate number.

I hope not! I just placed the order online about 30minutes ago, so if you're right hopefully I can cancel before it ships.

I chose this flexplate via the following method:
On the Autozone website I selected "1985 Chevrolet Truck K30 1 ton P/U 4WD 6.2L MFI Diesel OHV 8cyl" as my vehicle to get the site to match parts to my truck (as suggested by someone in another SS thread). Autozone recommended the Pioneer Automatic Transmission Flywheel FRA-142, and the description says it will fit transmission model THM400. Is that not the right transmission model, or are there further specs that I didn't pay attention to?

 

[Zeb]

No gasket. Just take your time and put everything back the way it belongs. No short cuts or half fast tricks. Good Luck. I will be here waiting for a report. Have a question? Please ask no question is bad except the ones you don't ask and break something. Doing it right the first time is the only way.

Thanks! I'll be sure to report back after I get it done (will probably tackle next weekend), or sooner if I need more help in the meantime (very likely).

 

[ezgn]

I hope not! I just placed the order online about 30minutes ago, so if you're right hopefully I can cancel before it ships.

I chose this flexplate via the following method:
On the Autozone website I selected "1985 Chevrolet Truck K30 1 ton P/U 4WD 6.2L MFI Diesel OHV 8cyl" as my vehicle to get the site to match parts to my truck (as suggested by someone in another SS thread). Autozone recommended the Pioneer Automatic Transmission Flywheel FRA-142, and the description says it will fit transmission model THM400. Is that not the right transmission model, or are there further specs that I didn't pay attention to?

I edited my first post above. Your fine, you got the right one. I put the part number in and Summit showed the one for a 1991 Chevrolet. I rechecked and realized that the same number came up as the correct part from other vendors. Sorry for the drama your good to go.

 

[Zeb]

I edited my first post above. Your fine, you got the right one. I put the part number in and Summit showed the one for a 1991 Chevrolet. I rechecked and realized that the same number came up as the correct part from other vendors. Sorry for the drama your good to go.

No worries! Thanks for following up so quickly.

 

[Skeptical Kitty]

If I missed this higher up in the thread my apologies. On a 1998 LMTV what is the size of the bolts that go thru the flex plate and into the flywheel? They have 3 groves cut across the head making them look almost like a castle nut. Are these anything special? Grade" etc? Asking for a friend who may have lost one.....

 

[cucvrus]

If I missed this higher up in the thread my apologies. On a 1998 LMTV what is the size of the bolts that go thru the flex plate and into the flywheel? They have 3 groves cut across the head making them look almost like a castle nut. Are these anything special? Grade" etc? Asking for a friend who may have lost one.....

Present Conflict Vehicles TMs

Find TM's related to Present Conflict Vehicles in this forum. Which includes HMMWV, FMTV, and Heavy Armored trucks. - No posting of threads

www.steelsoldiers.com

Please check out this forum. I think they will be able to supply you with an answer to this issue on the LMTV. This is the good ole CUCV site. Happy Holidays.

 

[Skeptical Kitty]

Perfect! Thank you!

 

[Zeb]

Starter gave up. Here we go! Will check back in once the job is done or it gets too late in the evening to finish

 

[cucvrus]

I said this before. If you have the starter out and you know nothing about how long it has been on the job. take it to a professional rebuilder. I never wait for complete failure of anything. most times it is going to fail in the farthest and most in opportune time that can be imagined. I always pull glow plugs when I experience hard starts and same for starters. if they are coming off and I don't know history. They will be rebuilt. Nothing is worse then unreliable vehicles and 3equipment. Doe's it cost money? Yes. But so do wreckers, roll backs and down time. Happy Holidays.