GQ diesel gearbox ?

Submitted: Tuesday, Sep 30, 2003 at 22:06
ThreadID: 7522 Views:1603 Replies:6 FollowUps:3
This Thread has been Archived
I noticed on the weekend that whilst decending a few steep hills i found myself slightly accelerating to keep my speed up where is my other Patrol (4.2 efi) on the same hill i had to be braking to keep my speed down...
Is that the diesel compression working or more a ratio difference?
Both manuals in low range 1st gear..._____________________________________________

_____________________________________________
Back Expand Un-Read 0 Moderator

Reply By: Member - Bigbear - Tuesday, Sep 30, 2003 at 22:33

Tuesday, Sep 30, 2003 at 22:33
Hi
As a general rule the diesel compression will work far better at braking than a petrol motor.
Reason behind this is that the diesel has far greater compression than a petrol motor.
Happy descents
Bush Bappo's 4WD Club
Get out there & have a look
AnswerID: 32435

Reply By: Truckster (Vic) - Wednesday, Oct 01, 2003 at 08:40

Wednesday, Oct 01, 2003 at 08:40
Mate of mine has the same thing with his GQ TD42 Manual, where Im going the pucker factor of 1999090 onto the seat in the auto, he is accelerating to just move! @#^%%@^%#%^s me off

So its not abnormal.
AnswerID: 32459

Reply By: David N. - Wednesday, Oct 01, 2003 at 10:05

Wednesday, Oct 01, 2003 at 10:05
Yes- this is an age old argument- but I have always believed the Diesel gives better engine braking.(Have driven both many times 4WDing.)
Some will disagree- bit like the Nissan/Toyota thing! (The Nissan is better! LOL)
Who'll take the bait?
Cheers
AnswerID: 32466

Follow Up By: Hilly - Thursday, Oct 02, 2003 at 22:26

Thursday, Oct 02, 2003 at 22:26
I have to bite David. My 4.2 litre diesel 80 series crawled down slopes better than my 4.2 litre diesel GU Patrol does. Lower low range gearing in the transfer case. Simple as that.

*sigh*

Hilly
0
FollowupID: 23351

Follow Up By: David N. - Friday, Oct 03, 2003 at 13:06

Friday, Oct 03, 2003 at 13:06
You're not telling me something I didn't know....
Lower overall gearing (gearbox x transfer case x diff.ratio) will always give better engine braking. That's one of the common problems with many new 4WDs- they just don't have low enough ratios for serious 4WDing.
Cheers
0
FollowupID: 23380

Reply By: Steve from Drive Systems Victoria - Wednesday, Oct 01, 2003 at 18:54

Wednesday, Oct 01, 2003 at 18:54
Petrol models have a higher ratio final drive too. 3.9:1 as opposed 4.1:1.
AnswerID: 32524

Follow Up By: Red Rover - Wednesday, Oct 01, 2003 at 20:29

Wednesday, Oct 01, 2003 at 20:29
Hi, not all petrols have 3.9's. I know the deluxe ones did - poverty packs were 4.1's. Mavericks were 3.9s in petrols i believe. Having said that mine with 4.3 diffs still only just crawls as slow as a diesel with 4.1's.
0
FollowupID: 23247

Reply By: Martyn (WA) - Wednesday, Oct 01, 2003 at 21:52

Wednesday, Oct 01, 2003 at 21:52
Voxson,
Normal normal, as diesel engine braking is good it's seen as an advantage as mentioned before, if you are looking to resolve the "problem" if you see it as one, I find it a good excuse to buy more accessories to increase the weight so you have a greater mass to overcome the engine braking effect............ Hows that for logic???Keep the shiny side up
AnswerID: 32550

Reply By: Eric - Wednesday, Oct 01, 2003 at 22:02

Wednesday, Oct 01, 2003 at 22:02
voxson.
This question keeps coming up but no one tells the real story, the reason that diesel is better is because of the throtel buterfly, on the petrol at idle very little air gets into the cylinder so there is no compression, on the diesel except some old bangers there is no throtle buterfly so a lot of air gets into the cylinder and therfore lots of compression. Eric.
AnswerID: 32552

Sponsored Links

Popular Products (13)