old skool too cool Posted March 26, 2014 Report Share Posted March 26, 2014 whats up so I noticed in 4th gear I have a lot of vibration. 3rd gear is good but in 4th around 60 I noticed a lot of shake coming from engine only when on the gas. 1st Datsun so not sure if this is just something im gonna have to deal with at higher speeds or you guys thinking anything else. Don't wanna have to put money in dynamat as it is loud and lots of vibrations so if anyone can help id appreciate it. Quote Link to comment
ggzilla Posted March 26, 2014 Report Share Posted March 26, 2014 Not normal. Check the drive line center bearing. Quote Link to comment
old skool too cool Posted March 26, 2014 Author Report Share Posted March 26, 2014 you think thatd be it I would think the energy would be transferred down there and that's were shake would be coming from but im still a 19 year old newbie haha. Actually you may be right haven't checked it out yet but I will. Quote Link to comment
heretic Posted March 26, 2014 Report Share Posted March 26, 2014 check your motor mounts & carrier bearing.... I've never owned a 520 so I'm assuming they have carrier bearings. Quote Link to comment
wayno Posted March 27, 2014 Report Share Posted March 27, 2014 Does the 520 have a carrier bearing? I believe that the 520 has one single long driveline. Quote Link to comment
old skool too cool Posted March 27, 2014 Author Report Share Posted March 27, 2014 it has one single drive line pretty sure two carrier bearings one each side. what would I look for how would I tell if bad? if bushings on bearings are bad new carrier bearings come with new bushings right. Quote Link to comment
datsunaholic Posted March 27, 2014 Report Share Posted March 27, 2014 520s don't have a carrier bearing. Could be tires or a bad u-joint. Quote Link to comment
datzenmike Posted March 27, 2014 Report Share Posted March 27, 2014 You're right wayno, should be a single driveshaft. Doesn't mean it can't be a bad U joint though. If badly worn the driveshaft can be shoved off center by engine torque and as it's turning almost 5 times for every turn of the rear wheels it's sure going to HUMM loudly. Old skool... There are two U joints one at the transmission end and one at the rear differential. Grasp the driveshaft at each U joint and push up and pull down, then side to side with it in gear. Try twisting it to make it rotate. There should be ZERO movement if the U joints are good. Don't be afraid to use a bit of force, they can handle it. Other causes of vibration are... A balance weight has fallen off the driveshaft. Look for a clean area where it was. The drive shaft is damaged and bent from hitting something. A piece has broken off one of the front or rear brake drums. A balance weight has fallen off one of the front or rear wheels or otherwise needs to be balanced. Tire damaged. Raise each one and spin by hand while watching the tread for lumps. Rim bent..... see above. The bolts between the engine and the transmission are loose. The rear transmission rubber mount is broken or loose. Gently pry with a length of 2x4. The rubber will move slightly but you shouldn't be able to dislodge the transmission from the mount. One or both rubber engine mounts are broken or loose. See above. Quote Link to comment
old skool too cool Posted March 27, 2014 Author Report Share Posted March 27, 2014 cool guys I appreciate it thanks mike learning a lot on this site. determined to make this car sick so ima be up here a lot. Im gonna check this out tomorrow ill post back up see how things go. Sounds like drive shaft problem fersure seeing those symptoms match up. Getting into 4th has a unbalanced washer type feel coming from hood and definitely not tires or anything like that since it only comes on while accelerating. Quote Link to comment
old skool too cool Posted March 27, 2014 Author Report Share Posted March 27, 2014 alright I have play in my driveshaft. I can make the shaft itself turn somewhat, and both u joints have a little play while in first. Does this mean im gonna have to replace both? Also no balance weight as there was a clean flat spot like mike said. I noticed a little leak of transmission fluid by u joint connected to end of tranny. Its actually really easy to turn a little so whats your thoughts guys? Quote Link to comment
wayno Posted March 27, 2014 Report Share Posted March 27, 2014 alright I have play in my driveshaft. I can make the shaft itself turn somewhat, and both u joints have a little play while in first. Does this mean im gonna have to replace both? Also no balance weight as there was a clean flat spot like mike said. I noticed a little leak of transmission fluid by u joint connected to end of tranny. Its actually really easy to turn a little so whats your thoughts guys? If you have the tools to change the U-joints, then change them, but it's sounding like you have thrown the balance weights off, so take it to a driveline shop and have them replace the u-joints and balance it, and in the meantime you should empty your transmission of fluids, change the rear seal, and when you get the driveline back, install it and fill the transmission with fluid, and you should be good to go. If this is a daily driver, then you have an issue, find another 520 driveline and have it checked/serviced, then empty the tranny of fluids, pull the old driveline, replace rear seal, install new driveline, fill tranny with fluids, and your good to go. Personally I hope you have another car to drive, you do not want to drive this vehicle with an out of balance driveline. The play you need to check for is not play while turning the drive shaft, it's sideways play in the u-joints themselves, most the time one has to remove the driveline to get a good look at it, unless it's about to fall apart, that one can see without removing the driveline. Quote Link to comment
old skool too cool Posted March 27, 2014 Author Report Share Posted March 27, 2014 fuck that ima figure it out myself may take a min since its my first time but whatever ujoints are 15 bucks a pop gotta learn sometime. Thanks for advice though im digging this site a lot. im youtubing it now doesn't seem to bad ill see how goes worst comes to worst ill take it in but that's gonna be last resort. IT is my daily driver though why you thinking that would that be an issue? If fix u bolts and etc wouldn't that be good to go although it is unbalanced so there might be some problem there still a newbie so idk. Quote Link to comment
wayno Posted March 27, 2014 Report Share Posted March 27, 2014 U-joints are not easy to replace in a Datsun truck, they are very hard to get out, then you have to put the new ones in without dislodging one or more of the needle bearings, you definitely need a good heavy duty vice. Quote Link to comment
wayno Posted March 27, 2014 Report Share Posted March 27, 2014 Here is a link about replacing u-joints. http://community.ratsun.net/topic/2329-u-joint-replacement/ 1 Quote Link to comment
datzenmike Posted March 28, 2014 Report Share Posted March 28, 2014 Definitely get the shaft balance properly or it will still vibrate and the new U joints will suffer for it. If replacing the U joints, mark the three pieces so that they go back together in the same relationship with the new joints. Quote Link to comment
TENDRIL Posted April 11, 2014 Report Share Posted April 11, 2014 if you dont have the proper tools to replace the u joints. dont do it. bring it to a shop, drive shaft work is fairly cheap, plus like mike said it will need to be balanced properly also some tire shops have the ability to balance them. Quote Link to comment
datzenmike Posted April 12, 2014 Report Share Posted April 12, 2014 You need only a large hammer and a slot screwdriver. A vice helps but not totally needed. Quote Link to comment
ggzilla Posted April 12, 2014 Report Share Posted April 12, 2014 What is a slot screwdriver, and how is it used to change the u-joints? Quote Link to comment
datzenmike Posted April 12, 2014 Report Share Posted April 12, 2014 Well a traditional bladed or flat screw driver. I use it to poke the C clips out of the U joints. Anything similar will do. 1 Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.