Thud / thunk sound shifting from reverse or neutral into drive. (1 Viewer)

[Pyrenees]

2001 LX 470, 177k mi. Owned for one year. Pretty well-maintained before my ownership. Starts, runs, drives and shifts flawlessly every single day. One thing I have noticed is that when I put it in reverse in a parking lot and then shift to drive, I get a dull THUNK sound from the drivetrain that I can feel resonate through the body, and this is what I'm curious about.

Idle speed is normal, 700-1000 depending on the day or if it's a cold start, so I don't think it's that. Sometimes if I pause in neutral for a second or two on the "reverse to drive" trip, it won't make the THUD. But most days it does. There is no issue in any other circumstance, it shifts smooth as butter up/down.

What is this most likely? Can I grease some things in the drivetrain to try and help it? I saw the FSM page with the lube points but admittedly I've never had a vehicle like this before so I have no idea how to do that.

Ask me all the questions you want. Thanks!

 

[suprarx7nut]

Here's my take on this phenomenon, recently having improved it on my 99 with 272k miles.

It could be the following and is likely a combination of many, if not all.

1. Front diff bushings.
2. CV Axle play at the spline interface within the diff and at the hub flanges. @2001LC has some really good pictures and videos on this.
3. Driveshaft play in U joints
4. Companion flange spline play
5. Rear diff spline play
6. Wear within the diff gears

I would investigate each of these more or less in the order I wrote them. #1 having the most bang for buck and #6 having the least (or at least, the highest likely cost to fix).

I did #1, 2 and 4 and cannot see any of #3. After doing 1, 2 and 4 my thud seems to be reduced, but it is not gone. I think the remaining play is from the rear diff/axle and wear within the front diff. I might address part of #6 when/if I do a front locker, but otherwise I'll live with the remaining thud.

 

[Pyrenees]

Here's my take on this phenomenon, recently having improved it on my 99 with 272k miles.

It could be the following and is likely a combination of many, if not all.

1. Front diff bushings.
2. CV Axle play at the spline interface within the diff and at the hub flanges. @2001LC has some really good pictures and videos on this.
3. Driveshaft play in U joints
4. Companion flange spline play
5. Rear diff spline play
6. Wear within the diff gears

I would investigate each of these more or less in the order I wrote them. #1 having the most bang for buck and #6 having the least (or at least, the highest likely cost to fix).

I did #1, 2 and 4 and cannot see any of #3. After doing 1, 2 and 4 my thud seems to be reduced, but it is not gone. I think the remaining play is from the rear diff/axle and wear within the front diff. I might address part of #6 when/if I do a front locker, but otherwise I'll live with the remaining thud.

Thanks for the detailed reply. Reminds me of when I was troubleshooting VSC. "It could kind of be anything". Next time I have the 100 up on a lift for something in particular I'll reference this and see if there's something with obvious slack. The thud noise is not anything out of the ordinary for an older vehicle and I've noticed no drivability issues.

 

[LETSROLLEM]

2001 LX 470, 177k mi. Owned for one year. Pretty well-maintained before my ownership. Starts, runs, drives and shifts flawlessly every single day. One thing I have noticed is that when I put it in reverse in a parking lot and then shift to drive, I get a dull THUNK sound from the drivetrain that I can feel resonate through the body, and this is what I'm curious about.

Idle speed is normal, 700-1000 depending on the day or if it's a cold start, so I don't think it's that. Sometimes if I pause in neutral for a second or two on the "reverse to drive" trip, it won't make the THUD. But most days it does. There is no issue in any other circumstance, it shifts smooth as butter up/down.

What is this most likely? Can I grease some things in the drivetrain to try and help it? I saw the FSM page with the lube points but admittedly I've never had a vehicle like this before so I have no idea how to do that.

Ask me all the questions you want. Thanks!

'98 LC 223k. I have this IDENTICAL issue, and have been consistently researching it. I have greased ( with moly and the suggested grease for the ujoints) every zerk on the truck according to the FSM. Replaced sway bar support bushings and I have 2 OEM front diff support arms w/ bushings, all new FEBEST top and bottom rubber cushion washers and a new FEBEST front diff plate bushing ( the one that is integrated in the front diff cover plate ). I'm dropping it off tomorrow to have all this installed, along with some other preventive maintenance, for my upcoming Rocky MTN Nat'l Park trip. I have a feeling replacing the components on the front diff will help to all but eliminate my "thunk". If not, next up is rear upper and lower control arms, as I have read, this could contribute as well. I'll keep you posted on my results.

 

[Pyrenees]

I have greased ( with moly and the suggested grease for the ujoints) every zerk on the truck according to the FSM

Not to hijack my own thread, but I'm interested to know what you used. I've seen the diagram but haven't lubed it.

 

[LETSROLLEM]

Here is what I use. The Sta-lube brand of moly-graphite can be picked up at your local Harbor Freight. I think it's around $6/tube. I use that for the slip yokes only. I'm sure you could use it everywhere but I like to conserve it just for the slip yokes (pumped in until purges out of the collar per FSM). The Mobil I (ordered on Amazon) is used on my ujoints and my SPC greaseable front UCA's. Hope this helps. Headed out now to drop it off at Goode Offroad here in Dallas for my install of the parts for my front diff. The owner was a master tech/service dept head foreman at Toyota of Dallas for 20 years and he also told me that he and a few other guys put the team together that is associated with TRDparts4u and did installs of offroad accessories. He started his own shop and is a LANDCRUISER enthusiast. I'm having him go through my entire rig for some PM and to address some issues I am experiencing. He is familiar with the "thunk" and assures me we will track it down. I'll let you know

 

[2001LC]

You can check your front drive shaft to hub flange play in many different ways. Here's one easy fast way wheels on the ground.
Most common D-N- R clunk.


New no clunk


Worn hub flange and axle teeth/splines cause this. It's due to improper wheel bearing service.
Hub flange:

New OEM

Shot ready to fail. Front drive shaft outer axle splines/teeth

New OEM

 

[2001LC]

Keep in mind axle to hub flange play is just most common.

Next in line is front differential bushings. I don't get near as much results from replaces the bushing. But on high mileage ~20 year old they are contributors to the shifting D-N-R clunk.

 

[LETSROLLEM]

Keep in mind axle to hub flange play is just most common.

Next in line is front differential bushings. I don't get near as much results from replaces the bushing. But on high mileage ~20 year old they are contributors to the shifting D-N-R clunk.

Update to my previous posts above, I had my shop (Goode Offroad in Dallas--20 year Toyota Master Tech) replace all 3 front support arms and bushings, he contacted me and I am going to have him do the drive flanges and a bearing replace/repack. He already did the support arms and bushings and said that dramatically improved what "thunk" I had and that there was some "slop" in the drive flanges, this will eliminate the "thunk/thud" I had from "R-D", he assures me. I pick it up Thursday so I will post my results here. I am doing a $$$ refresh on SEVERAL things for my upcoming Rocky Mtn Nat'l Park, Grand Teton and Yellowstone trip in August. I wanted to get some things done prior to leaving, for peace of mind. This being one of them. I am also having TB, WP, and new radiator put in. Coolant flush with Toyota Red coolant, RR Diff actuator clean and checked, new spark plug tubes and cam seals and new rotors, new alternator and drive belt and tie rods. Should be a new vehicle after all this! Then just routine driveway maintenance for the next 90-100k miles!

 

[l3n0x]

I wonder if there is any benefit of replacing the flanges only and not the cv’s (which are probably worn as well if the flange is)

 

[LETSROLLEM]

I wonder if there is any benefit of replacing the flanges only and not the cv’s (which are probably worn as well if the flange is)

I already had new OEM CV's installed a few months ago. If it's in your budget it wouldn't hurt, but it would depend on the wear to the axle shaft splines. If they appear in good shape and not worn, they should still be tight in new flanges. But others might be able to comment with more experience. I try to do all my work myself, to an extent, but I didn't have the time or tools to do some of the things on my to do list, so I just had him knock em out since he was in there anyway.

 

[apdxyk]

Too many 'errors' in FSM in regards to the A343F AT. I call the dipstick calibration incorrect, and the incorrect fluid level is the main culprit. All of the above arguments are valid, I just think that they are consequential. I usually vacuum 3.8 to 4.5 qts of ATF first time I service the 4-speed AT. Overfill causes obligatory thuds, underfill causes whining.

 

[2001LC]

I wonder if there is any benefit of replacing the flanges only and not the cv’s (which are probably worn as well if the flange is)

Short answer! Yes! I do it often. Best results are combining with new axle (FDS, AKA CV's) also.

 

[LETSROLLEM]

Ok here goes: (All this done in preparation for my Rocky MTN Nat'l Park, Grand Tetons Nat'l Park and Yellowstone, leaving in 3 days!) 1998 Toyota Landcruiser 2UZFE with 222,500 miles

*Replaced both front diff support arms with OEM (the entire assembly w/ the integrated bushings)
*Replaced front diff cover bushing
*New OEM Genuine Toyota Radiator
*Coolant flushed and replaced with Genuine Toyota Ext Life "Red"
*Replaced upper and lower radiator hoses with HPS Silicone hoses
*Replaced thermostat
*Replaced Thermostat water inlet housing
*Replaced timing belt
*Replaced water pump
*Replaced drive serpentine belt
*Replaced spark plug tubes and cam seals and new valve cover rubber grommets at bolts
*New wheel bearings and races
*New drive flanges
*New Denso alternator
*New fuel pump
*New entire air box and tube assembly
*New metal heater T's
*New outer tie rod ends
*New rotors (pads are new)
*All 8 brand new Denso coil packs and Denso Iridium plugs

The Good:

I had a pulsating feeling and a soft brake pedal while coming to a stop ~20-15-10-0 mph, thought it might have been the dreaded master cylinder piston and/or booster. Just so happens it was worn/warped rotors. Brakes are amazing now, they feel great! I also had a slight "thud" from the front when I would let off the gas momentarily and coast for a second and then get back on the gas, it is completely gone due to the new front diff bushings. Just feels tighter. It drove good before, but now it just feels "right".

The Bad (my initial primary issue):

The "clunk/thud/thunk" from "R-D" is still there, although seems less violent. I was hoping the bushings would solve it, but I'm thinking it may be something I'll just have to live with. It is non-existent if I shift from "R" then to "N" pause a split second then shift to "D". So I guess that will be my habit from now on. The last thing I have read it could be is the rear upper and lower control arms. So when the bank account recovers, I'll order the kit from Metal Tech and throw them on and hope for the best.

All that being said, if anyone near the Dallas/Ft Worth area is ever looking for and stand up group of professionals and a great shop with outstanding communication and knowledge, check out Mike Goode at Goode Offroad on Switzer Drive on the East side of Dallas. The team they have there know their stuff! They are Toyota enthusiasts, especially Landcruisers. I was drooling over several rigs they had parked out front when I dropped mine off. Their number is 469-556-7752. I'll be taking mine there for anything and everything. Their prices are awesome. The owner is a Toyota Master Tech and worked at the largest Toyota Dealer in Dallas for nearly 20 years and still has all his ASE and Toyota certifications. Hope this post helps

 

[MTrun]

Just fixed my drive / reverse clunk and think post #2 nailed it. There are a lot of elements that stack up. In my case the print culprit was a set of aftermarket CVs that had slop in the drive flanges. I bit the bullet and went to OEM CVs and it made all the difference in eliminating my driveline clunk.