Engine/Transmission (1994 - 1998) Replacing front gear case on 1998

[Dieselnut59]

Hello. I have read numerous threads about the "KDP" fix, but I need to fix the results of a KDP. It backed out years ago, right after getting the truck used. I JB Welded the the crack, replaced the front cover gasket and the crankshaft seal and it has been fine for nearly 100,000 miles. Truck is now one of our company service trucks and has developed a major oil leak somewhat suddenly. Our service guy removed the front cover, resealed the area around the housing crack and packed everything as full of silicone as he could, which slowed the leak. He also resealed the vacuum pump and replaced the gasket where the vacuum pump mounts to the engine. I am thinking the gear case has developed another crack near the injection pump. What all parts will I need to get and what are the part numbers? Also, any tips about removing the cam would be greatly appreciated. We are not willing to tackle the gear removal and installation, but instead want to do the whole cam shaft. Thanks for any advice. Per searching threads here, I found the following part numbers:

Gear case: 3936256

Gear case gasket: 3938156

Front cover gasket: 3918673

I will also need the following and would appreciate part numbers if yall have them:

Injection pump mount gasket

Vacuum pump mount gasket

Fuel transfer pump gasket

Front crankshaft seal

Valve cover gaskets

Valve cover washers



Thanks again and please fill me in with anything else I may be forgetting.

John

 

[LNaugle]

I would get the cpl# and call cummins, also suggest speedi-sleeve and seal for crankshaft. you will also need the side cover gasket. I use snap-on flexible magnets and clothes pins to hold the lifters up... . works on all years. I know thats alot of magnets but like insurance policy compared to wooden dowels. (and we do this stuff for a living)

 

[Dieselnut59]

I would get the cpl# and call cummins, also suggest speedi-sleeve and seal for crankshaft. you will also need the side cover gasket. I use snap-on flexible magnets and clothes pins to hold the lifters up... . works on all years. I know thats alot of magnets but like insurance policy compared to wooden dowels. (and we do this stuff for a living)

Thanks for the suggestion. I have been kinda worried about the wooden dowel method. We have an account with Cummins so I will definitely be calling them.

 

[Bob4x4]

The dowels have worked fine for me for many years. There is no need for any side cover to be touched.

 

[Shadrach]

Hello. I found the following part numbers:
Gear case: 3936256
Gear case gasket: 3938156
Front cover gasket: 3918673
I will also need the following and would appreciate part numbers if yall have them:

Injection pump mount gasket 3969698 ( o-ring )
Vacuum pump mount gasket 3008400
Fuel transfer pump gasket 3939258
Front crankshaft seal 3804899 ( kit ) or 3937111 ( bare seal ) or 3802820 seal / sleeve assy
Valve cover gaskets 3930906
Valve cover washers 3910824 o-rings or 3935449 grommets
Timing pin housing o-ring 3915772
Timing pin o-ring 3913994
Grid heater gaskets 3969988 ( 1 or 2 depending on year ) required only if you remove the intake horn
Shad

 

[jhenderson]

Just for the heck of it, check the oil pressure switch. I was helping a friend on a '96 we thought had a front cover or crank seal leak. Oil all over the front of the motor and the damper had 2 missing, 1 broken bolts. It turned out to be the pressure switch. I don't know how the oil migrated forward to the lower front but it did. The motor was loosing about a quart per hour.

 

[Dieselnut59]

Hello. I found the following part numbers:

Gear case: 3936256

Gear case gasket: 3938156

Front cover gasket: 3918673

I will also need the following and would appreciate part numbers if yall have them:



Injection pump mount gasket 3969698 ( o-ring )

Vacuum pump mount gasket 3008400

Fuel transfer pump gasket 3939258

Front crankshaft seal 3804899 ( kit ) or 3937111 ( bare seal ) or 3802820 seal / sleeve assy

Valve cover gaskets 3930906

Valve cover washers 3910824 o-rings or 3935449 grommets

Timing pin housing o-ring 3915772

Timing pin o-ring 3913994

Grid heater gaskets 3969988 ( 1 or 2 depending on year ) required only if you remove the intake horn

Shad

WOW! Thank you Shadrach! It is kind members like you that help make this website work! I appreciate your help. No matter how good a parts department is, it is always better to have part numbers in hand. Thank you for your assistance!



@jhenderson, Great idea. Although we definitely know the leak is coming from an area between the front gear cover and block, near the injection pump (after extensive pressure washing), but we will check the oil pressure switch too. It has had problems before and we replaced it. My 1996 also has an erratic oil pressure gauge and a similar oil leak. I will check the oil pressure switch on it also. Thanks again for the help!

John

 

[Dieselnut59]

I would also love if yall have the part number for the dowel pin itself. I almost forgot about that, since it came out several years ago. Also, if anyone knows the number for the oil pressure sender. I am going to go ahead and replace it at the same time, as the gauge is sometimes erratic. Thanks!

 

[LNaugle]

personally i would do the side cover gasket because its not often you are in there that far... unless your not pullin the ip to save time, which being a service truck, you usually dont want to be workin on it. means your not makin money with it. as far as the dowels go , i think some older guys are set in there way and not up for something that might be easier or better... if doin at home and tryin to save money, they are cheaper.

 

[Stein]

I would also love if yall have the part number for the dowel pin itself. I almost forgot about that, since it came out several years ago. Also, if anyone knows the number for the oil pressure sender. I am going to go ahead and replace it at the same time, as the gauge is sometimes erratic. Thanks!

I did the kdp fix a few days ago. . I looked up the pin number in case it was missing. . I came up with 3900257 for my truck. Im not sure if there all the same.

 

[Shadrach]

P/N 3900257 is correct for any older 5. 9. The new gear housing has a hole for the dowel which is smaller in the front than in the back making it impossible for the dowel to come out. It's a big job so take your time and do it once. Make sure the housing bolts are locktited as well as I have seen them come out too.

BTW For those who do not know DO NOT try to pull the gear off the cam and leave the cam in the block as a short cut. Although it can be pulled off in the engine to reinstall the gear it needs to be heated in an oven so the heat is even and then dropped onto the cam while still hot. Trying to do this while the cam is still in the bock is darn near impossible. You will either not get the gear on all the way, as is usually the case, and you risk the chance of pushing the rear cam plug out the back of the block and that mean either pulling the trans or the engine itself. I know of one case recently where the "mechanic" tried to heat the gear with a "rosebud" torch and because it is hard to get the heat even and then you have to quickly push it onto the gear it didn't go on all the way. They ended up wrecking the gear ( split it when it was "tapped" to go on ). The short cut ended up costing 2 extra days and nearly a thousand extra dollars.

The wooden dowels work well. They need to be long enough to tie together in pairs with big elastic bands when pulled up. The back ones of course need to be shorter. Just taper the end down so it is a tight fit into the tappet.

The oil pressure sender is p/n 3923200 ( for a 97 ESN - should be the same )

Have fun Shad.

 

[Dieseldemon]

P/N 3900257 is correct for any older 5. 9. The new gear housing has a hole for the dowel which is smaller in the front than in the back making it impossible for the dowel to come out. It's a big job so take your time and do it once. Make sure the housing bolts are locktited as well as I have seen them come out too.



BTW For those who do not know DO NOT try to pull the gear off the cam and leave the cam in the block as a short cut. Although it can be pulled off in the engine to reinstall the gear it needs to be heated in an oven so the heat is even and then dropped onto the cam while still hot. Trying to do this while the cam is still in the bock is darn near impossible. You will either not get the gear on all the way, as is usually the case, and you risk the chance of pushing the rear cam plug out the back of the block and that mean either pulling the trans or the engine itself. I know of one case recently where the "mechanic" tried to heat the gear with a "rosebud" torch and because it is hard to get the heat even and then you have to quickly push it onto the gear it didn't go on all the way. They ended up wrecking the gear ( split it when it was "tapped" to go on ). The short cut ended up costing 2 extra days and nearly a thousand extra dollars.



The wooden dowels work well. They need to be long enough to tie together in pairs with big elastic bands when pulled up. The back ones of course need to be shorter. Just taper the end down so it is a tight fit into the tappet.



The oil pressure sender is p/n 3923200 ( for a 97 ESN - should be the same )



Have fun Shad.

I have been removing the gear and replacing the front gear housing and have had no problems at all I heat the gear in powder coat oven to 400 line the marks and push it on then tap it with a dead blow hammer to seat the springs and tappets will hold the cam in place and keep it from moving this will take half of the time that it takes to remove the cam and lift pump rockers and push tubes. But you do it the way you feel is best for you

 

[Shadrach]

I'm glad it worked for you, most people can't get it right, so I don't recommend it, especially for rookies. Shad.

 

[Bob4x4]

lol most Cummins shops do it that way..... it's all about making money. Dodge dealer,Cummins dealers and ex cummins guys too.

 

[GAmes]

The oil pressure sender is p/n 3923200 ( for a 97 ESN - should be the same )

The oil pressure sender changed in '98. It has a different wire plug. The catalog from Genos shows both types.

 

[Shadrach]

The oil pressure sender changed in '98. It has a different wire plug. The catalog from Genos shows both types.

Thanks I didn't have a 98 ESN handy so I used my buddy's 97 ESN Shad