02/14/10 Transfer case question and a Motor rebuild update

[superslidestyle]

It seems that the transmission and transfer case need to move back about 8" in. in order to have clearance to drop the motor back in.  The front differential gets in the way of the oil pan so there's not a whole lot of room to maneuver in there.  Anyways, as I'm draining the tranny and transfer case, I noticed that GL-5 gear oil came out of the transfer case as well.  I know most other vehicles take gear oil in the transfer case but the Xterra repair manual says it should take Dex/Merc II/III ATF.  The guy at Autozone and at Pep Boys confirmed that, so now I feel a bit lost.  Does ATF sound right?  If so, would the Lucas Oil semi-synthetic ATF work?

Also, I finally got the pistons, rod bearings and main bearings back from swain after paying $306.00 and they did a great job!  I will get pictures up soon.  Took them to the machine shop and the guy there had the crank balaced out to 10/10 on the counterweights which means that the motor parts and the engine block didn't suffer too much from the overheating which in turn means less machining needed.  
It also turns out that I won't be using ARP head bolts.  They are $260 a set and just seems like too much money now.  I am still getting the Centerforce Dual Friction clutch kit however from 4x4parts.com for $435 (S/H included). I like the fact that they support the Nissan offroad community so I'll give them the business.

[SteeevO]

on the T-case ATF VS. Gear oil issue... Yes the factory recommends using ATF but gear oil can be used. Calmini even ships gear oil with their crawler gears.

[ultrapc40]

I remember reading somewhere that if you have a standard, they use gear oil in the T case, and if you have an Auto, they will use ATF.

[Bobby B.]

I use Amsoil GL4.  Works great.

Tried the Mobil 1 synthetic trans fluid and got so much bearing noise I took it out immediately.

With a manual trans, if a particular seal fails, fluid can migrate between the trans t-case; that's why they say use the same fluid.  From what I understand, there really isn't a way for the fluids to pass and get mixed with the auto trans, though I could have heard wrong. 

I've had no issues with the GL4 oil for years.  It was the same price per quart as the recommended Nissan Matic D fluid anyway. 

[superslidestyle]

But what am I supposed to use in there?  I already bought the Lucas semi-synth. ATF for the transfer case.  Can I still use it even though I have GL-5 in the tranny?

[Bobby B.]

Well, according to Nissan, you're supposed to use the Matic-D trans fluid. If you really want to dig into compatibility, work backwards from that.

Use what you bought.  If it doesn't work out for you, change it.

[superslidestyle]

OK, quik update.  Here are pics of the pistons with the SWAIN ceramic coating on the domes (tops) and poly-moly coating on the piston skirts, rod bearings, and main bearing surfaces.  These are supposed to attract oil to them and provide a temporary slippery surface to prevent metal-to-metal contact IN THE EVENT OF OIL STARVATION, like rock crawling or something like that.  Also extends the oil change interval from every 3000 miles to 7500 miles and extends the overall life of the motor by adding an additional 150,000 miles to the engines life.





Also here are some pics of the replacement header from an aftermarket made from CHINA steel.  Made thicker which is good but ports on the inside are smaller and cast is much, much more rough on the inside.  A port and polish is an absolute must for these pieces.




Here are closeups of the rough casts on the inside.




These are the results after the ports have been cleaned up.

[superslidestyle]

Update 01/04/2010:

Machine shop found a large crack on the pass. side head where the camshaft is at.  Will need to replace entire head (w/out distributor hole) and redo the port and polish on it.  If anyone has one, or know of someone who has one, I'll take it off your hands.

[Ruination Fan]

I am not 100% sure, but i believe the heads from an R50 (1996-2000)pathy or the Infiniti version (Qx4 from '97-2000) and the Quest from '99-'02 should work? I know there are a couple R50s and Qx4s and Quests down at the yard over on Oceanside about a month ago.

[superslidestyle]

You are correct.  Heads from 96-2004 VG30E motors are the same so long as the engine code is the same.  The VG30B motors have a different head due to different compression and accessory mounting configuration. 

G & S Machine Shop was able to scout another head for $160.  At least I picked up the block and will start installing it in the engine bay.  Pictures to follow.

[superslidestyle]

Update 01/26/10

Motor is partially assembled and ready to be dropped in if it wasn't for all this rain.  I do however, need to remove the exhaust down pipes, Y-pipe section, torsion bar assy., and T-case just to move the transmission back the 8" or so I need to drop the motor.  This far in I might as well drop the tranny and put new seals on the T-case, input and output shaft.



This is where the water pump mounts and requires agressive porting to remove bad castings.




This is the bottom of the motor prior to installing the oil pan.





Swain-coated pistons and cross-hatched piston bore machined 0.020" over.

[superslidestyle]

Just got both heads back, wainting on a Centerforce Clutch Stg. II to arrive in the mail so I can drop in the motor.

[superslidestyle]

I finally got the Centerforce Dual Friction Clutch:  $175 NEW on Ebay!

[superslidestyle]

Finished the porting on the replacement head also.  Before and after pics step by step.