Pajero 4WD Club of Victoria Public Forum Pajero 4WD Club of Victoria Public Forum

Go Back   Pajero 4WD Club of Victoria Public Forum > General Information > Mechanical

Mechanical Discussion of mechanical matters

Reply
 
Thread Tools Display Modes
  #1  
Old 25-02-20
markc markc is offline
Senior Member
 
Join Date: Oct 2007
Location: Brisbane Sth East
Posts: 342
Default Torque Convertor Lockup kits, Good or Bad technical discussion.

Edit by admin: This thread has been separated from another more general NX Pajero thread, that discussed the pros and cons of transmission lock-up kits. This post by markc has stimulated discussion that took the original thread off-topic, so was separated into its own thread.

Transmission lock up kits only increase the load on engine and gearbox when locked at lower revs that don't allow the torque converter to unlock and the engine to make power breathing at higher revs with lower stress

If you have a exhaust temp gauge fitted you'll see exhaust temps significantly rise as the engine lugs putting greater loads on engine bearings, combustion pressures and piston ring wear.
Add to this that you are taking some of the mechanical advantage away from the gear box by not allow the torque convertor do its thing.

Follow the manual, manually leave the gear box in 4th when towing reasonable loads ie > 1500kg. Use the sports shift to change gears and keep rpm between 2000~3000 with moderate throttle. Be aware of gbox temps and ease off and down shift if needed on long climbs. 4th is a one to one ratio so when in 4th apart from oil shear when the torque convertor unlocks = heat and higher torque output there is no = ZERO load on the gearbox

I'm sure I'll get plenty of contradictions over this reply but with a trade in diesel fitting and a 20 years as a mechanical engineer with a masters degree I look deeper than a glossy sales pitch.
Reply With Quote
  #2  
Old 26-02-20
cruisn06's Avatar
cruisn06 cruisn06 is offline
Valued Member
 
Join Date: Jan 2011
Location: Perth WA
Posts: 688
Default

Quote:
Originally Posted by markc View Post
Transmission lock up kits only increase the load on engine and gearbox when locked at lower revs that don't allow the torque converter to unlock and the engine to make power breathing at higher revs with lower stress

If you have a exhaust temp gauge fitted you'll see exhaust temps significantly rise as the engine lugs putting greater loads on engine bearings, combustion pressures and piston ring wear.
Add to this that you are taking some of the mechanical advantage away from the gear box by not allow the torque convertor do its thing.

Follow the manual, manually leave the gear box in 4th when towing reasonable loads ie > 1500kg. Use the sports shift to change gears and keep rpm between 2000~3000 with moderate throttle. Be aware of gbox temps and ease off and down shift if needed on long climbs. 4th is a one to one ratio so when in 4th apart from oil shear when the torque convertor unlocks = heat and higher torque output there is no = ZERO load on the gearbox

I'm sure I'll get plenty of contradictions over this reply but with a trade in diesel fitting and a 20 years as a mechanical engineer with a masters degree I look deeper than a glossy sales pitch.
You set the lock up to unlock at certain points, I dont tow, but if I floor it in 5th anywhere below 2300rpm it will unlock until i back out of it. a product is only as good as its end user.

or if I choose for it to remain locked up all the time, which i normally do i run it through the gears droppings to 4th for passing. then selecting 5th again. never had any issues or problems.
__________________
07 Mitsubishi Pajero Shorty - Currently rolling around Africa

Insta: https://www.instagram.com/wrongturnadventure/
Website: https://wrongturn.com.au/
Reply With Quote
  #3  
Old 26-02-20
Dicko1's Avatar
Dicko1 Dicko1 is offline
Valued Member
 
Join Date: Dec 2014
Location: Cairns, FNQ
Posts: 5,766
Default

[QUOTE=Dicko1;627288]You will get contradictions for sure. Especially as your talking rubbish. A masters degree in mechanical engineering means bugger all mate....you blokes keep thousands of spare part shops in a thriving business.. I,ve been involved in automotive engineering for 40+ years...means bugger all.
__________________
Dicko FNQ


2014 NW with all the usual stuff plus more.
Having lots of friends on facebook is the same as having lots of money in monopoly...both meaningless.

.

Telegraph X camper
Reply With Quote
  #4  
Old 26-02-20
Jasonmc73 Jasonmc73 is offline
Valued Member
 
Join Date: Jun 2019
Location: Brisbane
Posts: 832
Default

Quote:
Originally Posted by markc View Post
Transmission lock up kits only increase the load on engine and gearbox when locked at lower revs that don't allow the torque converter to unlock and the engine to make power breathing at higher revs with lower stress

If you have a exhaust temp gauge fitted you'll see exhaust temps significantly rise as the engine lugs putting greater loads on engine bearings, combustion pressures and piston ring wear.
Add to this that you are taking some of the mechanical advantage away from the gear box by not allow the torque convertor do its thing.

Follow the manual, manually leave the gear box in 4th when towing reasonable loads ie > 1500kg. Use the sports shift to change gears and keep rpm between 2000~3000 with moderate throttle. Be aware of gbox temps and ease off and down shift if needed on long climbs. 4th is a one to one ratio so when in 4th apart from oil shear when the torque convertor unlocks = heat and higher torque output there is no = ZERO load on the gearbox

I'm sure I'll get plenty of contradictions over this reply but with a trade in diesel fitting and a 20 years as a mechanical engineer with a masters degree I look deeper than a glossy sales pitch.
So that renders locking a torque convertor as the original manufacturer of stacks of trannys do absolutley useless then & obviously people especially whom tow & use well designed lockup kits will use far more fuel from all the extra load outlined
By the sound of things they even increase their combustion chamber pressure locking torque convertors obvioulsy through burning stacks of fuel!!!

Most Auto's lock these days, I guess by the sounds of things you've debunked that idea & use far less fuel.

There must be a way we can neutralise this lock business so we can keep combustion pressures down & burn less fuel, especially when loaded up

Zero load in 4th on gearbox, no load at all. geez thats the gear we should stay in then as no load zero load, almost like a bypass for the gearbox once we hit 4th.
Reply With Quote
  #5  
Old 26-02-20
Keithyv's Avatar
Keithyv Keithyv is offline
Valued Member
 
Join Date: May 2018
Location: Perth
Posts: 699
Default

Quote:
Originally Posted by markc View Post
Transmission lock up kits only increase the load on engine and gearbox when locked at lower revs that don't allow the torque converter to unlock and the engine to make power breathing at higher revs with lower stress

If you have a exhaust temp gauge fitted you'll see exhaust temps significantly rise as the engine lugs putting greater loads on engine bearings, combustion pressures and piston ring wear.
Add to this that you are taking some of the mechanical advantage away from the gear box by not allow the torque convertor do its thing.

Follow the manual, manually leave the gear box in 4th when towing reasonable loads ie > 1500kg. Use the sports shift to change gears and keep rpm between 2000~3000 with moderate throttle. Be aware of gbox temps and ease off and down shift if needed on long climbs. 4th is a one to one ratio so when in 4th apart from oil shear when the torque convertor unlocks = heat and higher torque output there is no = ZERO load on the gearbox

I'm sure I'll get plenty of contradictions over this reply but with a trade in diesel fitting and a 20 years as a mechanical engineer with a masters degree I look deeper than a glossy sales pitch.
What a load of old cobblers.
Who's talking about locking the torque converter at lower revs?

Stock in 4th or 5th the TC unlocks at the sniff of load - I could not tow a small caravan at 100km/h without it constantly locking and unlocking on flat ground at the slightest change in load.
TC lockup kit solves that.

Not sure about increasing load on engine and gearbox and higher combustion temps, where did that come from?
__________________
2014 NW MY14 3.2 DID GLX-R Auto. Champagne in colour!
MM Lockup mate. King KCRS-35 rear springs. Monroe Gas Magnum TDT rear shocks. 3M color stable tint all round. Spare wheel lift kit. 'Dynamat' in all doors. Pioneer AVH-Z5150BT Head Unit. Upgraded Speakers. Rear USB outlet. Factory nudge bar with LED light bar. Provent catch can. LED interior lights.
Reply With Quote
  #6  
Old 26-02-20
outbackogre's Avatar
outbackogre outbackogre is offline
Valued Member
 
Join Date: Jul 2010
Location: Melbourne
Posts: 450
Default

I tow a 1.6 tonne caravan in 4th gear at 90-95 kph with rpm at about 2400. The trans is locked most of the time on the highway. I have no gauges to tell me trans temps, but I'm guessing they'd be acceptable. I'm happy with this and don't believe I need a lockup kit.
__________________
My friends call me Rob; you can call me .... Rob.
-------------------------------------------------------------
MY12 NW GL DiD auto. 2" MD Lovells/Bilstein lift. Bushskinz underbody protection. Home made rear platform with sliding boxes above and lots of space underneath.
Reply With Quote
  #7  
Old 27-02-20
penski's Avatar
penski penski is offline
Junior Member
 
Join Date: Mar 2013
Location: Brisbane
Posts: 35
Default

Quote:
Originally Posted by markc View Post
Transmission lock up kits only increase the load on engine and gearbox when locked at lower revs that don't allow the torque converter to unlock and the engine to make power breathing at higher revs with lower stress

If you have a exhaust temp gauge fitted you'll see exhaust temps significantly rise as the engine lugs putting greater loads on engine bearings, combustion pressures and piston ring wear.
Add to this that you are taking some of the mechanical advantage away from the gear box by not allow the torque convertor do its thing.

Follow the manual, manually leave the gear box in 4th when towing reasonable loads ie > 1500kg. Use the sports shift to change gears and keep rpm between 2000~3000 with moderate throttle. Be aware of gbox temps and ease off and down shift if needed on long climbs. 4th is a one to one ratio so when in 4th apart from oil shear when the torque convertor unlocks = heat and higher torque output there is no = ZERO load on the gearbox

I'm sure I'll get plenty of contradictions over this reply but with a trade in diesel fitting and a 20 years as a mechanical engineer with a masters degree I look deeper than a glossy sales pitch.
I have a lockup kit fitted and would have to agree with you. I thought it was just me. I have set mine conservatively so it doesn't stay locked too low in the rev range but find the engine load and fuel consumption are always higher when towing 2.2t in 5th at 100kph than when i drive with the lockup kit off and shifting to 4th when needed as in the past. It always locks in 4th regardless as confirmed by the RPM. Mine will also stay locked in 5th too when a touch over 100kph in good conditions. I have towed over 10,000 km's now with the kit fitted and trying many different scenarios. Engine load is usually 15% to 20% higher cruising in 5th than 4th.
__________________
MY12 NW Pajero Platinum II, ARB Deluxe winch bar, MM Tow Bar, Optima Blue Top Battery with Redarc SBI12 Isolator, OME Suspension, Tekonsha P3 Prodigy Brake Controller, Bridgestone D697's, Polyairs, Bushskinz IC and Sump Guards, LRA 81l aux fuel tano.
Reply With Quote
  #8  
Old 27-02-20
Keithyv's Avatar
Keithyv Keithyv is offline
Valued Member
 
Join Date: May 2018
Location: Perth
Posts: 699
Default

Quote:
Originally Posted by penski View Post
engine load and fuel consumption are always higher when towing 2.2t in 5th at 100kph than when i drive with the lockup kit off and shifting to 4th when needed as in the past.
What has the difference between driving in 5th and 4th got to do with the lockup-kit?

What about the difference when towing in 5th with & without the lockup kit?

How can you compare fuel consumption (with or without lockup kit) when you are driving in 2 different manners?

All I know is in my NW, in 4th or 5th, the TC would unlock with the slightest of extra load (hill / wind etc) with a corresponding instant rise in monitored trans temp.

How that is placing 'extra' load on the engine is beyond me.
Where do you think all the extra gearbox heat comes from? It's all the extra work the engine has to do.

Quote:
Originally Posted by penski View Post
Engine load is usually 15% to 20% higher cruising in 5th than 4th.
Not sure how this relates to TC lockup?
__________________
2014 NW MY14 3.2 DID GLX-R Auto. Champagne in colour!
MM Lockup mate. King KCRS-35 rear springs. Monroe Gas Magnum TDT rear shocks. 3M color stable tint all round. Spare wheel lift kit. 'Dynamat' in all doors. Pioneer AVH-Z5150BT Head Unit. Upgraded Speakers. Rear USB outlet. Factory nudge bar with LED light bar. Provent catch can. LED interior lights.
Reply With Quote
  #9  
Old 27-02-20
Jasonmc73 Jasonmc73 is offline
Valued Member
 
Join Date: Jun 2019
Location: Brisbane
Posts: 832
Default

Quote:
Originally Posted by penski View Post
I have a lockup kit fitted and would have to agree with you. I thought it was just me. I have set mine conservatively so it doesn't stay locked too low in the rev range but find the engine load and fuel consumption are always higher when towing 2.2t in 5th at 100kph than when i drive with the lockup kit off and shifting to 4th when needed as in the past. It always locks in 4th regardless as confirmed by the RPM. Mine will also stay locked in 5th too when a touch over 100kph in good conditions. I have towed over 10,000 km's now with the kit fitted and trying many different scenarios. Engine load is usually 15% to 20% higher cruising in 5th than 4th.
I think your correct myself.

Engine load will be higher when you use a higher ratio gear with 2.2t load & use more fuel.
Reply With Quote
  #10  
Old 27-02-20
Keithyv's Avatar
Keithyv Keithyv is offline
Valued Member
 
Join Date: May 2018
Location: Perth
Posts: 699
Default

Quote:
Originally Posted by Jasonmc73 View Post
I think your correct myself.

Engine load will be higher when you use a higher ratio gear with 2.2t load & use more fuel.
Again, what has this got to do with a lockup kit?
Locking up the TC may enable you to lug along in 5th but it does not mean itís causing any issues, just enabling someone to do it.
__________________
2014 NW MY14 3.2 DID GLX-R Auto. Champagne in colour!
MM Lockup mate. King KCRS-35 rear springs. Monroe Gas Magnum TDT rear shocks. 3M color stable tint all round. Spare wheel lift kit. 'Dynamat' in all doors. Pioneer AVH-Z5150BT Head Unit. Upgraded Speakers. Rear USB outlet. Factory nudge bar with LED light bar. Provent catch can. LED interior lights.
Reply With Quote
Reply

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Torque Convertor Lockup Meter old Jack PB -PC Challenger 2009 - 2014 10 05-12-13 10:09 AM
Nm 3.5Lt torque convertor issues johndickson Mechanical 0 07-10-13 11:09 PM
Manual lockup of torque convertor 1178tony Mechanical 4 04-05-11 07:33 PM
Torque convertor lockup Ian Johnston Mechanical 8 07-07-10 05:30 AM
torque convertor lockup nev smith Generation 3 Pajero 6 13-07-08 06:36 PM


All times are GMT +10. The time now is 12:09 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2020, vBulletin Solutions, Inc.