Thursday, July 17, 2014

New Gearbox Upgrade Project Part 2 - Disassembled

Tiong has fully disassembled my RS5F70A gearbox to it's individual components. Before showing you the actual porn pictures, here's a diagram from a USDM B15 Sentra's Technical Service Manual illustrating the 70A gear components. Please don't ask me if this is an auto or manual gearbox.

The shift control components.

The gear ratios on every 70A gearbox are not all the same and differ according to the market and engine the gearbox is mated to. A USDM RS5F70A gearbox mated to a SR20DE engine on a Sentra B15 has the following gear ratios per the technical service manual.
  • 1st - 3.3333
  • 2nd - 1.955
  • 3rd - 1.286
  • 4th - 0.926
  • 5th - 0.7333
  • Final drive - 4.176

A USDM 70A gearbox mated to a QG18DE has nearly the same gear ratios except 5th gear which is shorter (lower speed) @ 0.756. Apparently from what I read in the SR20-Forum, the pinion shaft from a QG18DE 70A will not mate correctly with the final drive from a SR20DE 70A gearbox. The gearbox I bought probably came from a JDM Nissan Primera P11 which has the following gear ratios when fitted with the QG18DE:
  • 1st - 3.333
  • 2nd - 1.955
  • 3rd - 1.286
  • 4th - 0.926
  • 5th - 0.7333
  • Final drive - 3.888

Disassembling the gearbox and counting the number of teeth of the final drive crown wheel/ ring gear showed that the crown wheel/ring gear had 70 teeth. All pictures courtesy of Bro Jacko. 

Pinion came up to 18 teeth.

70 divided by 18 gives you 3.888 final drive ratio. Didn't have a chance to count and confirm on the first to fifth gear ratios but I am hoping the above is correct. Will confirm when I have the chance to physically see the gearbox. Imagine getting to this point without even seeing the real thing :( 

Picture below of the input shaft, mainshaft and shifter rods with all the individual gears before further dis-assembly.

Another piccie of the mainshaft. Final drive ring gear is at the bottom right hand corner. 

Gears, synchros, etc are in excellent, like new condition. 5th gear and reverse actually shares a synchro. This is the first I've seen of a helical cut reverse gear with synchro. Most reverse I know are straight cut hence the gear whine when you reverse your car. Each and every individual part sealed and carefully labelled.

Nicely packed up. All packing and heavy lifting BST expended by Jack. Thanks Bro!

The biggest roadblock at this point is the shipping cost. As the package weights bout 40kg, the shipping cost one way to the US is via air freight is anything between 1K+ to 2K+ Gulp! Does anyone know or have contacts for a more economical shipping solution?

4 comments:

Zii said...

Wonder if this will fit on the QG15DE haha

Andrew Saw said...

Yes it will.

Zii said...

Hmmm, interesting, will look into this when I BOT the QG15DE. I heard the RS5F70A and the RS5F70V is about same just that the 70V has LSD where 70A doesn't have LSD correct me if I'm wrong

Andrew Saw said...

Theoretically the same but the differences extend more to just the addition of an LSD. The end cover, etc are all different so you cannot just bolt the LSD from a 70V to a 70A. Also good luck trying to find a 70V in this part of the world.