Go Back   The Navara Forum > D40 > D40 Engine

Thread Tools Display Modes

need some help with performance changes or upgrades
Old 02-06-2019, 06:20 PM
Hugopta Hugopta is offline
Junior Member
Join Date: May 2019
Location: Hong Kong
Posts: 9
Default need some help with performance changes or upgrades

Hey guys

Bough a 07 model about 2 months ago and bought it purely just to pull a boat at the coast which is about 5KM to the launch ramp and back.

Bit of background, I obviously did not do enough research but I felt I had a diesel mac help me out with the purchase, I picked the truck up for a really cheap price and guess what, engine blew shortly after.

I replaced it with the same YD 25 engine, with mileage between 60k and 90k thinking everything was good.

The guy that owned the truck before me really didnt give a crap about it any I have fixed most of the cosmetic items, paint work, body work, lights and so and still going on some smaller items to make the truck the nicest it can be for me.

It's a double cab, no diff lock, no 4X4 and it used to be based inland, I eventually got it to the coast.

It goes really nice on the open road no troubles, I do find it a little bit heavy on fuel if I listen to what other people get fuel wise. Towing the boat on the main roads, it does what it should do like any other truck, I dont expect it to blow me away in terms of performance towing a distance but it tows the boat no problems.

What I did however notice is that I recently visited a river for the first time which has a much shallower ramp then the ramp at the river I spend 98% of my time at, upon pulling the boat out I was very very surprised at how much the engine was laboring to get the boat out and I had to use more clutch then normal to get it out, after that I also smelled the clutch, but I didnt think much of it, this was the first time I retrieved the boat from a ramp so maybe my expectations were a bit high but I was very dissapointed.

Before I owned I use to rent the 2.5 petrol NP300 single cab and that pulled the boat out of ramps no problems so that is what I was basing my expectations on.

Went back home after that and had to back the boat up a driveway, no problem in doing so but I was smelling the clutch.

Went back to my river, this time with the steeper ramp, and for the hell of me I could not get the boat out, I think it might have been because the tide was super low so the concrete ramp becomes mud where the trailer is so as soon as you load the boat on the trailer the wheels just sink in, the trailer wheels that is as its in the mudd and the truck is on the concrete ramp.

The truck tires were also on a slippery part of the concrete slip but there was no way it was coming out, I had to get someone with 4X4 to pull us out and I smelt the clutch once again, rear tires were spinning with my attempts.

After that I had to put the boat in the boat house, smelt the clutch again after the wheels spinning on the grass.

I then spoke to a friend of mine who had the identical truck in the club cab and the identical boat, he said that he also struggled to get his boat out of ramps and had to use his diff lock which helped, he eventually chipped his truck which he suggested I do, removed the cat converter and that gave him 19KW extra.

There was a small leak on my turbo because of the incorrect gasket used but thats all fixed up and I dont have the truck long enough to know if it really made a difference the boat is nothing big, 19ft, probably 1.2 - 1.4 tons on the trailer.

Guys are my expectations just to high here and is this what the truck offers or is something else wrong? I know its a wide area to diagnose, friends have suggested I take it to a Auto clinic and let them balance the prop shaft, check the turbo out, remove the cat as well as chip it with the Uni chip Q plus.

Would really appreciate any help!
Reply With Quote
Sponsored Links

Old 02-06-2019, 09:52 PM
Old.Tony's Avatar
Old.Tony Old.Tony is offline
Join Date: Oct 2009
Location: Mid Coast Region, NSW, Australia
Posts: 15,306
My Mood:

Forget balancing the prop shaft for the time being - you'd only consider that if you were experiencing vibrations while driving and even then, it's more likely a uni joint or a bearing that's causing the trouble.

Boat ramps for manuals are always a problem, which is why so many of us that do tow have autos.

The reason manuals are a problem is because they have what's called a "Dual Mass Flywheel" (DMF) and not a "Single Mass Flywheel" (SMF). The DMF has a face that the clutch rubs against just like the SMF, but in the DMF this is very thin and prone to getting hot very quickly under load. The SMF has a lot of metal there and dissipates the heat a lot better, which is why many manual owners changed to SMF with heavy duty clutches.

If you had the 4WD version you'd have the option of using low range (4LO) which is what I do (even though mine's an auto).

Increasing the power output of the engine is only going to burn the clutch faster, unfortunately. The 4WD version is much better suited to work where traction is reduced.

Check out the FAQs by clicking here!

"Money can't buy happiness, but it does make misery a lot easier to deal with."
Reply With Quote

Old 03-06-2019, 04:54 PM
Hugopta Hugopta is offline
Junior Member
Join Date: May 2019
Location: Hong Kong
Posts: 9

Thanks man, that makes sense.

I guess it comes down to loss of traction, nothing I can do about that really.
Reply With Quote

Old 04-06-2019, 01:52 AM
bods's Avatar
bods bods is offline
Advanced Member
Join Date: Sep 2010
Location: Orelia, WA
Posts: 5,015

As mentioned above, the best thing you could do for it would be change the clutch over to a solid flywheel setup. That will help more than trying to get any more power out of it.
Reply With Quote

Old 04-06-2019, 04:34 PM
Hugopta Hugopta is offline
Junior Member
Join Date: May 2019
Location: Hong Kong
Posts: 9

Thanks for the feedback man, much appreciated!
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT +1. The time now is 04:21 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
| Home | Register | FAQ | Members List | Calendar | Today's Posts | Search | New Posts |