84 720 4x4 pinion and ring

[rnscustom]

I have an 82 vin 720 pickup , has the z24 so it’s a rebuild from a couple trucks I assume . Came with a spare rear that I need to use the gears out of . The one in the truck is 2wd gears and she just locks up in 4x4 . These are the numbers on the ring out of the spare ( according to the po belong with the front gears ) JH37:9 AB 3 9 21 . Anyone know what this set is and if they were 4x4 gears . Not sure I can follow any tags on the truck . Thanks everyone on the head and timing issues . Seems fine , need to time it but been busy getting back to regular work , Richard 

[datzenmike]

A Z24 in an '82 has been transplanted. October '82 and up are '83 model year, and have Z24s, Z20s and SD25 diesels.

 

The Z24 4x4s were 4.11 with a few 3.889. And the rear axle was a C-200. Earlier 4x4s were 4.375 and H-190 differentials. The C-200 is a Salisbury type with bolt on cover plate on the back with the gears inserted into a one piece axle housing and set. The H-190 is a bolt in from the front, removable 'third member' axle.

 

Yes the front differential ratio must match the rear ratio.

 

Your JH37:9 AB 3 9 21 is a 4.11. There were 4.11 C-200 and H-190 gear sets. The 4.11 ratio H-190 was used in some of the 2wd.

 

C-200 is 200mm diameter ring gear and larger will indicate relative strength.

The H-190 is 190mm diameter ring gear.

Needless to say C-200 and H-190 R&P gears do not swap.

[rnscustom]

Thanks again , I do have the c-200 bolt on cover . The gears are a little crusty so I’m going to clean them up and hope for the best . The pinion is still in , tried driving it out but no go , have to put it in the press . Gotta get back to regular work so the rear will wait a little while . The wedge I made for the timing chain worked well , kinda curved and tapered . I think it also held the tensioner in so I didn’t have to put much pressure on it ., can post it if you think it would be informative .Anyway you’ve been a great help , thank you !! Im probably going to scrap what is left of the spare diff. ( no gears or axles ) but if someone can use it I’ll post it for free ( shipping on them ) 

[datzenmike]

The C-200 gears have to be 'set' with gauges and shims for correct tooth contact. Or at least checked. The H-190 can be taken out as a unit and swapped.

 

I made this silly thing for a Z24. It's springy and when pushed down between the chains and guides pushes directly on the tensioner through the chain.

 

[rnscustom]

Yours is a bit nicer but exactly the same . Worked great . Thanks again for all the help , Richard