5th Gen 4Runner Drivetrain Rebuild: Driveshafts Rebuild

Table of Contents

Drivetrain

• Rear Axle Assembly Rebuild + Rear Axle Seal Replacement
• CV Axles Rebuild + CV Axle Seal Replacement + Front Wheel Bearings Replacement
  
• Driveshafts Rebuild

 

Driveshaft Removal


Removal of the rear driveshaft bolts connected to the third member was a challenge because of their orientation. Since the bolts can only be installed this way, it is a challenge to remove them when they have completely seized up after years of harsh weather conditions. I tried heating the nuts up and then using impact on the bolts. That didn't work. The only way I was able to get them off is by cutting them into pieces with an angle grinder. I first hand to cut the top of the bolt off to get it to move through the hole. Afterwards I had to cut the shaft on the opposite side because location of the third member prevented it from sliding out completely.


The same had to be done with front driveshaft bolts connected to the front differential. This was the most challenging part. I had to use smaller rotary tool and small cut off disks to reach into the given space.


Bolts cut into pieces.


Removal of the bolts connected to the transfer case flanges was a bit easier. I just heated them up until they were red hot and then used impact wrench to remove them.


The manual advises to mark the shaft and the flange so everything is balanced. After doing a bit of research, it seem that driveshaft is balanced to itself without being attached to the front differential and the third member. I still went ahead and made a mark with rotary tool. Since I was going to clean all the rust off of the driveshaft and the flanges, a maker wouldn't have worked.


The rear driveshaft came off after a few knocks with a rubber mallet.


Removal of the front driveshaft was a challenge. In order to get it passed the one of the frame members, you have to compress it. With the amount of rust and calcified dirt that accumulated over the years, I was not able to compress it more than an inch.


I had to scrape all that dirt off with a long screwdriver and them try to compress it again.


This time it gave in and all the grease came out of the zerk fitting opening.


It also helped to use a pry bar in the way shown in the photo to knock the driveshaft off of the flange. The flange has studs instead of the bolts, so in order to get the driveshaft removed I had to force it off of the studs.

 

Rust Removal and Painting


Both of the driveshafts removed from the vehicle.


Condition of driveshaft and U-joints.


I dedicated a good portion of the day to clean off a layer of rust that was as thick as a nail. The other portion of the day was dedicated to cleaning of all the rust and grease that the driveway and garage was covered in.


Driveshafts after rust removal.


To keep the driveshaft balanced I decided to use thin pieces of gorilla tape. Once painted, the metal under the tape would remain as a permanent mark.


Painting in progress.


All of the parts of the driveshaft aligned before installation of U-joints.

 

U-joint Removal


I rented ball joint press tool from AutoZone for this job. I would honestly say that this is not the right tool for the job if your U-joints look anything close to mine. I managed to press one cap out with this press with the help of another person.


The problem with the ball joint press tool is that it can only press out U-joint caps out of flat styled flange. The flange yoke on my 4Runner is angled, so the tool cannot even be placed on it properly. I ended up using 20 ton press for this job. To accommodate angled flange yoke, I had to modify 32 mm socket by cutting it at a slight angle. To press the caps out, I used 17 mm socket.


This was my setup for the angled flange yoke.


I used 35 mm (CV axle nut socket) for the for the slip yoke.

I have seen a special tool that you place on the U-joint to press it out. This way all of the force from the press comes down on the U-joint instead of on the cap that is stuck in the flange hole. This method seem to be the best one, considering that the caps can be seized up pretty badly. At one point I was applying so much force onto the cap that I thought that something is not right. It was about the same force as I would use to press out wheel bearings. The next thing I know, the socket pushes thought the hole and the whole setup comes flying in my direction.


To remove the caps I used chennellock pliers.


The other cap was then slightly pressed in using a punch and a hammer before being taken to the press to be pressed out. A little bit of grease helped a lot to get it moving smoothly.


To remove clips I used a punch and a chisel.


Whoever installed these clips was not thinking about the next person that would be removing them.


I couldn't get a punch in there to get it out, so I had to use a small chisel to grab onto the clip to get it to move.


One of the problems I had when pressing U-joints out was overpressing and damaging the sides of the flange.


I ended up correcting this mistake with a file.


Condition of the old U-joints.

 

OP, your doing an excellent job with your thread. Maybe I missed it but why did you initiate the rebuild? Rust?

thanks

 

Perseverance! These kinds of jobs keeps one "off the streets and out of trouble" lol.

 

There are days when I think I am pretty handy and than thread like this shows up.

OP how do you know or why do you have to balance the drive shaft. Aren't they balanced out of factory.

 

They are balanced from factory, but you have to make sure that all the parts are aligned the same way they came off before reassembly.

 

Drivetrain rebuild started with leaking rear seals (https://www.4runners.com/threads/5t...bly-rebuild-rear-axle-seal-replacement.36609/). Rust, age of components, and lack of care by the previous owner were really the main issues from the time I got this car.

Long Answer: I got feed up with it


I was just thinking about the mistakes I have done when purchasing a car for overland travel (https://www.4runners.com/threads/5th-gen-4runner-overland-build.36499/). At first I thought that I would buy a car, do all the preventative maintenance, build a camper, and hit the road. The reality was that every several months I would need to come back to use garage for an extended period of time to do major repairs.

My first mistake was that I bought an old car with 150k miles. At this mileage a lot of parts come to the end of their life span. If I was doing city driving, some of the parts could have lasted a little longer. With extensive off-roading, these parts failed almost immediately. After every long overlanding trip with off-road segments, I would need a garage for major repairs.

My second mistake was that I bought a car that spent 13 years in New York. People who live in the Southwestern part of the US are ignorant about rust, and some people who do dishonest businesses take advantage of that. Rust added to premature failure of stock parts. It also took repairs to a completely different level. I had to deal with layers of rust thicker than a finger nail, rubberized undercoating, deposits of salt, and seized up bolts and parts. I have been fixing all the cars I owned on my own, but I would have never imagine the hell I got myself into when I got this one. Repairs that could have taken 1 week, lasted easily for 1 month.

My third mistake was that I bought a complex car. it is 4WD truck with a bunch of bells and whistles. It is also very difficult to work on. The knowledge base, skills, tools and space required to work on vehicles like this are far beyond what I have imagined.

I guess everyone has their own battles in life. Maybe that was another reason why I kept on going with this rebuild. Mechanics where I live straight up refused to work on this car because of rust. One of them just told to scrap this car because of its age, mileage, and rust. By the time repairs were necessary, I already invested a lot into this build. This car was also my daily driver. I was put in a situation I had no way to back out of. It was either I take care of it once and for all, or I buy myself a cheap car as a daily driver and call this a project car that will seat in my driveway for years.

 

U-Joints Installation


I decided to go with Moog U-joints for this rebuild. Their super strength line comes with a zerk on a side making U-joints greasable.


Some say that having zerk on the cap is not ideal for off-roading because it can be damaged when going over obstacles. This is not a problem for the front driveshaft, but the rear driveshaft zerks can certainly be damaged.


I had these socket set screws for the stock U-joints, but never installed them. Moog U-joints take 1/4-28 socket set screws that I will have to buy from Amazon later on. For now I will keep the zerks.

 

Overgreasing Slip Yolks


When I was putting slip yolks back onto the driveshafts, I realized that there was old grease inside. It was difficult to put them back on with the zerks in place, since I was compressing air. I immediately thought to myself about proportion of grease to air in the slip yolks. After doing a bit of research on the topic I found out that I have been following wrong advice all this time. I have been overgreasing slip yolks to the extent that they acted as solid driveshafts. I ended up getting all the grease out of the slip yolks and leaving just the air. I will be adding 2 - 2-1/2 pumps of grease every 5k miles from now on.


On the sides is the amount of grease that came out from the rear driveshaft.


This is a portion of grease that came out of the front driveshaft.

Now I am just waiting for bolts to put everything back in place.

 

OP, you are correct, I am thankful that I live in the desert and don’t have to deal with rust.

I’ve done many how to threads on another forum and I know how much work it can be. I appreciate your efforts on this thread.

 

These projects build character....and wreck you lol! I hope you are young!