R33 gtr gearbox upgrades?

[BK]

You are correct, a loosely thrown around interval is 5000km, but that is largely dependant on the operator. Someone who is very skilled at changing gears in an H pattern dog box will cause little to no wear on the dog teeth faces. Same thing with a sequential with correctly setup strain gauge strategies correctly unloading the gears on shift, very little dog wear will occur. On the flip side someone just bashing a dog box around not shifting correctly will wear the flat sides of the dogs very quickly, to the point where they will jump out of gear on the slightest gear unload. This where km on box is not a good gauge for inspection, rather inspection intervals at X amount of hours, or x number events completed.

You are also correct in the dog gear replacement. The main shaft gears usually have dog teeth on the side an a separate sliding dog that matches to it. What you have to replace can only be determined on a box teardown, so it is not impossible to predict what you're likely to need. Sometimes with only slight wear on the dog teeth you can get prolong the gear or sliding dog needing replacement by regrinding the dog teeth from being rounded off to square again. This will buy you more time with needing to replace anything, but eventually round again and need to be replaced.

The biggest problem is that any of the above requires the box to be removed from the car, disassembled and inspected, possibly repaired, reassembled and reinstalled again - whether you replace anything or not. This is where the main cost in keeping a dog box alive is, not necessarily the cost of any parts that may or may not need to be replaced. When someone chooses to go dog engagement this has to be just accepted as the norm, and is the main reason why a synchro box makes more sense for a dedicated street only car.

[Butters]

Thanks for the reply !  

These guys do a dog box with the rings seperate from the gears - https://www.6xdgearbox.com/

They suggest a dog is $300 ish AUD. 

 

Anything like that available for the GTR ?

 

info for anyone interested

 

 

[RB335]

I have a new Series 3 box, haven't broken anything yet with around 700hp, I go easy into 3rd gear.

Have been tossing up about the sequentials.  Lately the word has been PPG = probably not, a few people who've had them haven't been too satisfied with how they hold up

A few big HP GTRs have switched to Samsonas and handling the power well.   Albins seems quite new to market, unsure how good they are and how they handle the power.  

Big money to drop on a gearbox.  I'm tossing up between Samsonas and Albins but will definitely want to know what's got the better track record on holding the power

Edited November 30, 2020 by RB335

[Predator1]

Its the torque that will kill the box and how its driven, anyway, I was in a similar boat, and I decided to go Albins.

[oktaytrz]

Here's a quote I got for a PAR gear 1-4 straight cut syncro with stock 5th.

Note from the gearbox shop: 

"the PAR sets work well with the upgraded 26-spline input shaft. It does require you upgrade your clutch to match with the GM style input splines."

 

This means new clutch, labour involved to take the box out (if you cant do it yourself), shipping to send the box to the shop (if you don't have a decent gearbox builder in your state) and to send it back. It all adds up quickly.

There's a few guys in WA using PAR gear sets and are very happy with it.

[Greekos]

updates, got my PPG dogbox back drives sooo much better after about 500km i can drive it without issues around town all different speeds, best way to explain is it loves direct shifts, it really isnt that bad to drive and i have to say once i got used to it i almost prefer it to a syncro box.

[BK]

Good to hear ! What parts got replaced again ?

[Greekos]

2nd gear, 3/4 inner hub,1/2 outer hub dogs had the gear-set isf refinished, the pressure changing gears is almost like stock, so it was definitely a assembly issue that caused my grief

 

[oktaytrz]

53 minutes ago, Greekos said:

2nd gear, 3/4 inner hub,1/2 outer hub dogs had the gear-set isf refinished, the pressure changing gears is almost like stock, so it was definitely a assembly issue that caused my grief

 

Do you mind uploading a video here mate? 

[Greekos]

iv been meaning to make a small vid so sure can