Jerking when I give it gas . (1 Viewer)

[stevenmichael]

Let me start off by saying I'm not a very good mechanic and I don't know the names of all the parts of the 4 wheel system . I have a 1997 lexus lk450 with the knob inside for front and rear locking diff .

The other day I noticed when I was giving it some gas when the light turned green that it started jerking like the rear end was slipping . I let off the gas and slowed down and it stopped .

It didn't do it again till I had a garage add grease to the drive shaft that goes from the rear diff that connects the rear wheels to a box in the middle of the truck . I'm not sure what that box looking thing is ,I think he called it a transfer case . Once they added the greasee to all the grease plugs the guy said it took a lot of grease .

When they lowered truck and pulled it out it was jerking really bad , It wasn't doing that when they pulled it in so he know something happened . He put it back on the lift and he pointed to the box where the drive shaft ended the transfer box I think that is what its called .

He put it in gear and it was making a noise and vibrating . He said to fix it he would have to put in a new one . He let the truck down again and as I was trying to drive back home I had to pull off the road as soon as I got on it because it was jerking so bad I started and stopped going very slow off the road and went in a circle in a parking lot till it finally stop jerking . This was all in distance of a mile . Once I was going down the road it was fine and I couldn't get it to jerk again .

I thought they may have put to much grease in it and something was having a hard time turning inside . All was good till the other day and it jerked again when I was gving it some gas after the light had turned green . that was last week and it hasn't done it again .but I have been taking off very slowly to try to keep it from doing it again .

The garage at the time they added the grease checked the box to make sure it had fluid in it and they showed me it was full . They also checked the rear diff fluid .

Does anyone know whats going on ? Is there a way for me to know if the jerking is in the drive shaft , the rear end or the box ?

I can't remember the last time I put it in 4wheel low and I don't think I have ever used the front and rear diff locking knob . Should I get on a gravel road and put it in low 4 wheel drive and run it for a while and should I try using the knob on the dash ? Are there any good video 's about the jerking or slipping action ?

I really don't know how to explain whats going on other than its not a smooth take off . It never does it until I'm stopped and I start moving again like at a red light or stop sign . It never does it while I'm driving and it only last a few seconds because I let off the gas right away .

The only time it did it for a mile was when I left the garage and they added grease to the drive shaft . I don't think the people at the garage ever worked on a lx450 before .

Any help will be greatly appreciated . It has 190,000 miles on it . Never been off road . It was my dads and I got it when he passed . I got it from him with about 150,000 on it . I let my daughter put 20,000 on it and I have put on the rest . I really like it and I want to try to keep it going if I can . Its my daily driver . Its just a regular stock lx450 ,its not the one in the photo I have for the forum . I just like that photo .

 

[mudgudgeon]

Are there any good video 's about the jerking or slipping action ?

Well. . . .




In all seriousness, never go back to that mechanic.
Sounds like they over greased the slip joint in the driveshaft. This can cause vibration.
The fact they thought they'd over greased something, and that they think the fix for their incompetence is too replace the transfer case tells you all you need to know.

I was gonna suggest post in the local Kentucky Clubhouse section, see if anyone has a reconnection for a local mechanic that knows cruisers

KY- Kentucky Landcruiser

forum.ih8mud.com

Doesn't look like it's a super active forum, but you might get a recommendation.


Is the jerking happening only when you give it a decent amount of gas? If you pull away gently does it happen?

 

[Kernal]

Ditto all abve, you need to find someone who knows this model, that would go a long way to figuring out your issue. IME most shops that don't work on Land Cruisers don't understand the driveline on this model and will just want to throw parts at it.

@stevenmichael : can you describe the jerking a bit more??

Does it occur when driving on loose dirt, gravel, grass?

Does it feel like the brakes are sticking, like something is holding
the vehicle back or dragging, sticking and releasing, or ????

What do you see with the tachometer (engine rpms) when
this happens, is the needle jerking around??

Are there any instrument cluster lights on (orange)?

Are all the tires matching (same size/design/brand)?

Any odd noises (chirping from the tires) when this happens ???

Has the transmission been serviced, fluid added or changed, before
the problem started??

Has there been any brake work done recently?

You could remove the grease fittings on the front and rear driveshaft slip yolks (?6mm IIRC) then drive around a day with the fittings removed; that should allow any excess grease to come out. As already mentioned, that mechanic likely overfilled the slip yolks with grease but then it was already jerking occuring before the vehicle was serviced??

This shows the slip yolk removed from the driveshaft, note the small grease fitting point up at 12 O'clock on the slip yolk on the right of the photo:

 

[mudgudgeon]

Yeah, I don't think the over greased slip joint is the problem. I think it's a separate issue, and a distraction.

The mechanic's attitude to it is a major red flag.

 

[BILT4ME]

Your description of the issue sounds to me like failed drive flanges on the front hubs or low oil in the transmission.

Unfortunately, not knowing the names of parts and how this works makes it more difficult, but we'll try to talk you through it and we'll (I) try not to be an a****** about it. Thanks for letting us know your level of understanding.

These trucks have a viscous coupler in the transfer case in the center of the truck, attached to the rear of the transmission.

Questions to try to help diagnose:
1) Does the engine rev up more than it used to when you are pulling away from a stop sign/light?
2) Do you hear or feel any grinding noises when pulling away from a stop sign?
3) Do you know how to place the truck into low range (short lever on the center console pulls back until it engages a different set of gears inside the transfer case)
4) If you place it in low range, does this problem go away?
5) Can you take a video while driving and starting and stopping in the driver's seat with the windows down so we can hear? (You must upload the videos to YouTube and then paste a link here in your reply)
6) Has there been any other maintenance or work done on the truck in the last 50,000 miles?
7) Has it been in any collisions?
8) Do you know how to check your engine oil level, transmission oil level, and power steering pump oil level?

We can walk you through this. We want to do this soon so that further damage does not occur.

You've already got three of the best guys on this forum working on this and we will post soon after you post something. We will try to use "layman's terms" to help you understand. All directions and locations we refer to are based on if you're sitting in the driver's seat. The "right" side will be the passenger side.

You can paste pictures right in with your replies and questions to help if you don't know something.

Just greasing the driveshafts should not cause the issue you are describing. Did they also change all the fluids? If so, what fluids did they change and what did they put in? Photos of receipts with your name and personal information covered will help.

 

[lcwizard]

It sounds like a transfer case issue. Assuming no one has done a part time conversion, there is a viscous coupling in the case that allows slip between the front and rear
while cornering as your inside wheels travel at different speeds than the outside while in a corner. If you had a conventional part time t-case and drove on the road in 4WD
the tires would chirp through corners. If the viscous coupling is sticking or failing, that could cause issues. You could go to a flat nonpaved field and put the truck in low
range, which should lock the t-case center diff, and see if it still shudders. Find a mechanic very familiar with the Land Cruiser T-case. There are modifications you can do to
eliminate the conveniences of electronic everything, like part time kits.

Contact the closest land cruiser club and get some recommendations for a mechanic. You're probably not going to be happy with the results from a local Pep Boys
or AAMCO.
I'm a west coaster so I can't say what's out in the SE with the exception of Nolan Grogan at Tilda Bogue in Mississippi, ACC in Georgia and Marshall at Trollhole in SC .

 

[fjbj40]

First thing is do not return to the garage you talked about!

They sound like they know nothing and as stated pumping the driveshafts full of grease is a big mistake!

You have come to the right place for help also. Very knowledgeable people here and probably some local to you that will help if you reach out to one of the clubs

 

[stevenmichael]

Well. . . .




In all seriousness, never go back to that mechanic.
Sounds like they over greased the slip joint in the driveshaft. This can cause vibration.
The fact they thought they'd over greased something, and that they think the fix for their incompetence is too replace the transfer case tells you all you need to know.

I was gonna suggest post in the local Kentucky Clubhouse section, see if anyone has a reconnection for a local mechanic that knows cruisers

KY- Kentucky Landcruiser

forum.ih8mud.com

Doesn't look like it's a super active forum, but you might get a recommendation.


Is the jerking happening only when you give it a decent amount of gas? If you pull away gently does it happen?

I never really punch the gas when I start to go after the light turns green so it can do it at a slow take off . If I let off and give it gas again it usually doesn't jerk . Thanks for the link I will see if I can find someone to look at it that knows whats going on .

 

[cruzinfj1]

Post a video of what its doing.

 

[stevenmichael]

Ditto all abve, you need to find someone who knows this model, that would go a long way to figuring out your issue. IME most shops that don't work on Land Cruisers don't understand the driveline on this model and will just want to throw parts at it.

@stevenmichael : can you describe the jerking a bit more??

Does it occur when driving on loose dirt, gravel, grass?

Does it feel like the brakes are sticking, like something is holding
the vehicle back or dragging, sticking and releasing, or ????

What do you see with the tachometer (engine rpms) when
this happens, is the needle jerking around??

Are there any instrument cluster lights on (orange)?

Are all the tires matching (same size/design/brand)?

Any odd noises (chirping from the tires) when this happens ???

Has the transmission been serviced, fluid added or changed, before
the problem started??

Has there been any brake work done recently?

You could remove the grease fittings on the front and rear driveshaft slip yolks (?6mm IIRC) then drive around a day with the fittings removed; that should allow any excess grease to come out. As already mentioned, that mechanic likely overfilled the slip yolks with grease but then it was already jerking occuring before the vehicle was serviced??

This shows the slip yolk removed from the driveshaft, note the small grease fitting point up at 12 O'clock on the slip yolk on the right of the photo:

View attachment 3339099

Does it occur when driving on loose dirt, gravel, grass? I have a hard time and have never been able to make it do the jerking on demand . I have not been on loose dirt , gravel or grass but I will get on it and see if I can make it jerk . It did the jerking thing really bad for about a mile of going very slowly in a parking lot right after the garage added grease in the drive shaft fitting . That was the worse it had ever done the jerking thing . I'm sure if it was filled with grease again it would do it again .

Does it feel like the brakes are sticking, like something is holding
the vehicle back or dragging, sticking and releasing, or ???? No the jerking only happens maybe once in 100 times ot 200 times of starting off at a light and as soon as I let off the gas for a second and give it gas again it goes away and doesn't happen again for a long time . I don't think the brakes have anything to do with it because one time I was just slowing down approaching a light without using the brakes at all and was almost stopped because it was a slight hill and the light turned green and I gave it gas it it did the jerking thing .

What do you see with the tachometer (engine rpms) when
this happens, is the needle jerking around?? I will have to get back to you on that I will see what happens . I always let of the gas right away as soon as I feel the jerking and it always stops and doesn't start back . The only time it keep jerking for any distance was when I left the garage after they filled the drive shaft with grease .

Are there any instrument cluster lights on (orange)? No light are on or come on when it jerks .

Are all the tires matching (same size/design/brand)? All 4 new Michelin tires regular road tires .

Any odd noises (chirping from the tires) when this happens ??? No only the jerking .

Has the transmission been serviced, fluid added or changed, before
the problem started?? No

Has there been any brake work done recently? When I had the new tires put on at the tire shop 2 years ago I think they checked the rotors and pads and all was good . I felt the first jerking about 6 months ago .

 

[stevenmichael]

Post a video of what its doing.

I will try but its so random I never know when its going to happen . I can't make it do it when I want it to . If I fill the drive shaft with grease again I could probably make it do it again to make a video .

 

[stevenmichael]

Your description of the issue sounds to me like failed drive flanges on the front hubs or low oil in the transmission.

Unfortunately, not knowing the names of parts and how this works makes it more difficult, but we'll try to talk you through it and we'll (I) try not to be an a****** about it. Thanks for letting us know your level of understanding.

These trucks have a viscous coupler in the transfer case in the center of the truck, attached to the rear of the transmission.

Questions to try to help diagnose:
1) Does the engine rev up more than it used to when you are pulling away from a stop sign/light?
2) Do you hear or feel any grinding noises when pulling away from a stop sign?
3) Do you know how to place the truck into low range (short lever on the center console pulls back until it engages a different set of gears inside the transfer case)
4) If you place it in low range, does this problem go away?
5) Can you take a video while driving and starting and stopping in the driver's seat with the windows down so we can hear? (You must upload the videos to YouTube and then paste a link here in your reply)
6) Has there been any other maintenance or work done on the truck in the last 50,000 miles?
7) Has it been in any collisions?
8) Do you know how to check your engine oil level, transmission oil level, and power steering pump oil level?

We can walk you through this. We want to do this soon so that further damage does not occur.

You've already got three of the best guys on this forum working on this and we will post soon after you post something. We will try to use "layman's terms" to help you understand. All directions and locations we refer to are based on if you're sitting in the driver's seat. The "right" side will be the passenger side.

You can paste pictures right in with your replies and questions to help if you don't know something.

Just greasing the driveshafts should not cause the issue you are describing. Did they also change all the fluids? If so, what fluids did they change and what did they put in? Photos of receipts with your name and personal information covered will help.

Questions to try to help diagnose:
1) Does the engine rev up more than it used to when you are pulling away from a stop sign/light? No it doesn't rev it starts off smooth and gets up to speed smoothly . Even when it starts jerking the engine doesn't rev up the truck it slows down like the rear end is slipping in the gears . As soon as I let off the gas it stops jerking and drives normal and will not happen again for a long time .
2) Do you hear or feel any grinding noises when pulling away from a stop sign? normally no noise at all . Only when I start off and it jerks and then I let off the gas for a second and it drives normal again .
3) Do you know how to place the truck into low range (short lever on the center console pulls back until it engages a different set of gears inside the transfer case) yes I can put it in low range . I have only put it in low to test it out to make sureit will go in and out of gear from high to low . I haven't traveled any distance on gravel in low .
4) If you place it in low range, does this problem go away? I haven't tried that yet . I will get out on a gravel road and see if I can get it to do the jerking thing . I can't make it do the jerking thing when I want to . I have tried . The only time it did the jerkig thing for about a mile was in the parking lot right after the garage put grease in the drive shaft .
5) Can you take a video while driving and starting and stopping in the driver's seat with the windows down so we can hear? (You must upload the videos to YouTube and then paste a link here in your reply) Its a very random thing . Maybe once a month but I'm not punching on the gas . I will try to punch on the gas at start off to see if I can make it happen if I can figure out how to make it jerk I will get a video on it . at the garage once he put it back up on the lift after it was jerking when he pulled it out the first time he startd it up and put it in gear on the lift and he gave it gas and it was jerking while he was giving it gas he went right to the transfer case and said it was coming from inside the case . I did ask him why putting grease in the drive shaft made it start jerking . He didn't know why . I ask if it could be coming from the inside of the drive shaft and he said probable not . Once it put it back on the grounmd and pulled it out it was still jerking as it was moving . I think he thought he missed something up because it was driving good before he added the grease . I didn't think I was going to make it back home . I had to circle a parking lot very slowly until it finily stop jerking when I gave it gas . Once it stopped jerking I slowly got up to 55 mph and drove home and stopped and started a bunch of times to try to get it to jerk again but could never get it to jerk again . after about a month of driving it did it again at a stop light on take off .
6) Has there been any other maintenance or work done on the truck in the last 50,000 miles? Just the oil and filter changes .
7) Has it been in any collisions? No
8) Do you know how to check your engine oil level, transmission oil level, and power steering pump oil level? Yes all the fluid levels are good . I wasn't sure about the fluid levels under the truck like the rear end drive or the transfer casre of the smaller round front end drive round thing . They did add fluid to the front round part . all the other levels were good . Once I find someone that knows about the truck I'll have them change all the fluids .

Just greasing the driveshafts should not cause the issue you are describing. ( it did cause the jerking to happen for about a mile right after it was filled with grease . I think over filled but I'm not sure . )
Did they also change all the fluids? (No they just checked the levels and only added to the front drum housing I don't know what that smaller drum is called but it looks like the rear one .)
If so, what fluids did they change and what did they put in? I'm not sure what they added to the front drum . Photos of receipts with your name and personal information covered will help.

 

[mudgudgeon]

@stevenmichael you can make responses easier for us to follow by hitting "Reply", then scroll through the quoted text and just hit enter where you want to respond. This breaks the quoted text into chunks

Example

I never really punch the gas when I start to go after the light turns green so it can do it at a slow take off .

this might be worth testing. Does it do it more frequently if you do punch it? Or if you're on an incline?

If I let off and give it gas again it usually doesn't jerk .

This may be because you've got the vehicle rolling, and reduced the strain/ load on the drive train

Thanks for the link I will see if I can find someone to look at it that knows whats going on .

If front hub drive flanges and birfield splines are worn out they can slip under high load. (Final connection between wheels and driveline) You'd normally hear a grinding noise if this is happening.
If this happens, you'd normally lose forward drive as all power is lost through the birfields spinning within worn flanges. In a four wheel drive vehicle, power goes to the point of least resistance.

A viscous coupling (VC) in the transfer case acts like a limited slip diff, and directs drive to the rear diff.
a seized viscous coupling will basically lock up the centre diff, so power is going to go to the rear diff regardless of slippage at the front wheels.
If this is happening AND you have worn-out front hub flanges it could mask the issue as the rear diff is going to get drive regardless of the problem at the front.
If the flanges are just starting to skip, combined with seized VC this might explain what you have happening.

 

[stevenmichael]

@stevenmichael you can make responses easier for us to follow by hitting "Reply", then scroll through the quoted text and just hit enter where you want to respond. This breaks the quoted text into chunks

Example


this might be worth testing. Does it do it more frequently if you do punch it? Or if you're on an incline? I will try doing this and see what happens .

This may be because you've got the vehicle rolling, and reduced the strain/ load on the drive train


If front hub drive flanges and birfield splines are worn out they can slip under high load. (Final connection between wheels and driveline) You'd normally hear a grinding noise if this is happening.
If this happens, you'd normally lose forward drive as all power is lost through the birfields spinning within worn flanges. In a four wheel drive vehicle, power goes to the point of least resistance.

A viscous coupling (VC) in the transfer case acts like a limited slip diff, and directs drive to the rear diff.
a seized viscous coupling will basically lock up the centre diff, so power is going to go to the rear diff regardless of slippage at the front wheels.
If this is happening AND you have worn-out front hub flanges it could mask the issue as the rear diff is going to get drive regardless of the problem at the front.
If the flanges are just starting to skip, combined with seized VC this might explain what you have happening. I didn't realize that so many different thing could be going wrong with just the jerkimg . I do know what right after the garage filled up the drive shaft it was a constant jerking no matter if I let off the gas while it was moving or not I was moving and it was still doing it so I went really slow in the parking lot for about a 1/2 mile till it stopped . I was afraid to get back on the road ,it was that bad . Why did it do the constant jerking when the drive shaft was filled with grease but once I drove around for a little bit it stopped and I couldn't get it to do it again ? In the photo at the start of this thread someone took a photo of the drive shaft and I can see threads . Coudd I have worn out threads inside the drive shaft and thats whats causing the jerking ?

 

[stevenmichael]

Ditto all abve, you need to find someone who knows this model, that would go a long way to figuring out your issue. IME most shops that don't work on Land Cruisers don't understand the driveline on this model and will just want to throw parts at it.

@stevenmichael : can you describe the jerking a bit more??

Does it occur when driving on loose dirt, gravel, grass?

Does it feel like the brakes are sticking, like something is holding
the vehicle back or dragging, sticking and releasing, or ????

What do you see with the tachometer (engine rpms) when
this happens, is the needle jerking around??

Are there any instrument cluster lights on (orange)?

Are all the tires matching (same size/design/brand)?

Any odd noises (chirping from the tires) when this happens ???

Has the transmission been serviced, fluid added or changed, before
the problem started??

Has there been any brake work done recently?

You could remove the grease fittings on the front and rear driveshaft slip yolks (?6mm IIRC) then drive around a day with the fittings removed; that should allow any excess grease to come out. As already mentioned, that mechanic likely overfilled the slip yolks with grease but then it was already jerking occuring before the vehicle was serviced??

This shows the slip yolk removed from the driveshaft, note the small grease fitting point up at 12 O'clock on the slip yolk on the right of the photo:

View attachment 3339099

Could my threads be worn down and that is what is causing it to jerk on take off ? Is there a way to know if they are worn down enough to cause problems ?

 

[stevenmichael]

First thing is do not return to the garage you talked about!

They sound like they know nothing and as stated pumping the driveshafts full of grease is a big mistake! How do you know when you have added the right amount ?

You have come to the right place for help also. Very knowledgeable people here and probably some local to you that will help if you reach out to one of the clubs

 

[Malleus]

Could my threads be worn down and that is what is causing it to jerk on take off ? Is there a way to know if they are worn down enough to cause problems

No, that's not your problem. We're guessing the problem is between the engine and the wheels. And that's a guess.

When you say the truck is jerking, are you driving straight ahead or turning (I assume it's straight ahead)?

Does the truck feel like it's driving over railroad ties (moving up and down) or does it feel as though it's lunging forward, pausing, and lunging forward again?

Just to confirm your description of the problem, there is no noise associated with the problem, just a feeling the truck isn't moving smoothly?

When the engine is running, but the truck is stopped (for instance, in your driveway), what lights do you see on the dash when you shift from H to L? You should see orange ABS and DIFF LOCK lights on the left side of the instrument panel, below the tachometer. You should shift the transmission into N before you do this. You can do it in P, but you will also get a red A/T P light on the right side of the instrument panel, below the speedometer, if you do.

 

[ozarkmud]

I may be missing something, but given the description of the jerking I was thinking more of a fuel pump filter sock issue.

 

[Malleus]

That's why I asked the questions I did...

 

[robnicko]

just a thought based on an issue I had a few years back with mine when it was exhibiting similar symptoms and ended up being rear driveshaft related.

I removed the rear shaft and separated the slip joint and cleaned thoroughly. Then I lubed it with moly grease and installed in the truck bolted to the transfer but before I bolted it to the diff I removed the zirk fitting, compressed the slip joint and whilst compressed put the zirk back in. Then I extended it and bolted to the Diff.

Im sure it was old grease that had hardened within the area near the zirk fitting that caused the binding which in turn caused the jerking / rumbling which shook the car upon acceleration.

Its been perfect ever since