Jump to content
SAU Community

General Gearbox Questions

G0DZLR
 Share

Recommended Posts

G0DZLR Mentor

G0DZLR

Posted
Posted

so after having replaced my blown 25DE box with a stronger 25DET box to cope with the obvious power gains of going from sub 100kws NA power to over 200kw forced, all is well apart from a couple of things.

firstly, when under mild load, 4th gear tends to crunch in, hence, you pretty much have to granny it into 4th otherwise youl hear a beautiful noise and feel it up your left arm. :) is this a sign of an aging box on its way out? clutch is bled properly too btw, every other gear theres no issue. is there anything i can do, without pulling it apart to prolong its life? additives or....im running castrol VMX80 in it atm. is there a thicker oil maybe i should be using

secondly, are 25DET speedo senders a different part to the 25DE ones...main reason is my speedo is pretty much half scaler, ie 20 is 40, 30 is 60, 40 is 80 etc...

help is much appreciated :down:

Link to comment
https://www.sau.com.au/forums/topic/316765-general-gearbox-questions/
Share on other sites
The Dan Grand Master

The Dan

Posted
Posted

Ageing box my friend.

What's the bet you paid top dollar for it to?

This should serve as another lesson to everyone else out there that a series one, or even series two gearbox IS NOT WORTH WHAT PEOPLE ARE SELLING THEM FOR.

Sorry to hijack it abit there mate, just sick of hearing about people buying these things for $1500 and then having to fork out another $1300 to rebuild them. I hope you didn't pay more than that.

You can try a different oil but it's not about how thick it is, it's how well the synchro operates in that oil. I wouls actually suggest a thinner oil like transmission fluid as it will help the synchro grab the gear easier. But be warned, it's a last stand and the gearbox may develop small leaks in about 6 months. Use the time to save for a rebuild

G0DZLR Mentor

G0DZLR

Posted
  • Author
Posted

hmm, anyone know what exactly i should use in this case then? someone did suggest to me a motul "shockproof" fluid? not sure what it is and where i get it but yeah. so far theres been no whines or bearing noises so i guess thats a good sign for now.

and thanks for the news daniel...:)

The Dan Grand Master

The Dan

Posted
Posted

The shockproof oil is made by redline and is very expensive. It CAN help sometimes but the last couple of cars I have put that stuff in, we have been having problems with it spitting it out when the box gets warm.

You could try the Motul Gear FF - part # 18-502-01 as it can help sometimes. I have put that into a few tired boxes and it works well.

If it doesn't, drain it out into a clean container so you can use it again after the rebuild.

Put in dextron 3 in the meantime. Should improve it out of sight failing the motul.

Alternatively, you might just have to shift slower :)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • MBS206
      Duncan's V37.......race car?

      By MBS206 · Posted

      Even more fun, leave all the ADAS stuff plugged in, but in different locations, hopefully avoid any codes!   And honestly, all these new cars with their weird electronics. Pull all the electronics out Duncan, and just shove an aftermarket ECU and if needed a trans controller in, along with a PDM. Make it run basic but race car styled!
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      To follow up a question from earlier too since I had the front bar off again (fking!) This is what is between the bumper and the drivers side wheel And this is the navigator side, only one thing but its a biggy! So basically....no putting coolers in the wheel arches without a lot of moving other stuff. Assuming I move to properly race prepping this car I'll take that job on and see how the computers respond to removing a whole bunch of ADAS modules
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      So I prepped the car for another track day on Wednesday (will be interesting to see coolant temps post flushing out and the larger reservoir, with a forecast of 3-14 being 20o cooler than last time I took it out). Couple of things to mention; since I am just driving the car and not taking a support vehicle, I took the rear seats out and just loaded the back up Team Trackday style. Look at all that space! To cover off removing the rear seat....it is weird (note the hybrid is probably different because it wouldn't have folding rear seats) Basically, you remove the lower seat base, very similar to a r series but it is a clip that pulls forward to release the base rather than it being bolted down. Easy Then, you need to remove the side section of the rear seat on each side. There is a 14mm head nut at the bottom of the side piece, the it slides upwards off a hook at the top to release; you also need to unhook the seatbelt from the loop at the top. Then the centre piece is weird. You need to release/fold the seats forward with the tab in the boot on each side From there, there are 2,x12mm headed bolts holding the rear of each seat to the folding bracket, under the trim between the rear seat and the boot (4x christmas tree clips there, they suck). The seat is out but you can see where the bolts attach to the bracket
    • RP1421
      S15 Spec R

      By RP1421 · Posted

      As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • joshuaho96
      R32 GTS (RB20DE) Injectors Replacement

      By joshuaho96 · Posted

      I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
×
×
  • Create New...