Since a year ago when I got the car it has shake whenever I let off the gas at lower rpms. Below 2500 or so it's really bad. Above that it gets better and is non existent in the 6000+ range.

It's not like vibrating but more of jolt every half second or so, but the speed of it changes with the speed of the car not rpms.

I just replaced all the bushings in the rear and just replaced the transmission mount but I noticed the driver side crossmember bushing is torn and has some play.

Anyone know where to get these bushings or at least a new crossmember?

 

rockauto.com sells the engine cross member mounts. There pretty cheap in price. You'll need to use a engine hoist to raise the engine just a little once the mount nuts are taken off.

 

I actually just dealt with a similar issue like this - turned out a u-joint was pooched and driveshaft was a bit out of balance...

 

Sorry for the lack of detail, I meant the transmission crossmember not the engine.

Weird question: Is baby blue (same color as carb top hat) the stock color for the driveshafts? If so I'll have to order the aftermarket one if it comes down to that. But I'm thinking it's the transmission crossmember bushings.

 

Doesn't sound like a driveshaft problem.. that appears as a lot of Clunking sounds when getting on or off the gas, shifting etc.

 

I have noticed a clunking sound when moving slow and putting it in first and when I shift from first to second. On/off the gas also has a clunk because it feels like something is loose and allows the u joint to fold up some, whether it's the u joint itself I don't know.

 

I'm going to order the aftermarket driveshaft from Mazdatrix but I had a couple questons about replacement.

1. Do I need a new tailshaft bushing? I saw them on Mazdatrix but I honestly don't know what they are.

2. Will I need new transmission fluid?

And any tips on replacement will help. I've taken the driveshaft off the diff and that is straight forward but I have no idea how it connects to the transmission.

 

It just slides in. If ypu jack the car up from the rear and pull out the driveshaft, you should lose minimal tranny fluid.

If you ha ent changed the trans fluid in awhile, this would be the most ample time to do it

And you shouldn't need a bushing, just a new tailshaft seal and you should be g2g

 

Thanks for the help man. I just put $50 worth of redline trans fluid in it so I'll probably just order another quart just in case.

 

You shouldn't even lost that much, just a dribble if you get the *** up high enough

 

Makes sense! Haha thanks.

 

I just got my driveshaft in and I tried to replace it but of course the rear flange doesn't match the bolt pattern on the diff.

The rear has been swapped to a gsl lsd but I thought it was an '83, so I just ordered the one that fits 83-85 5spd without even thinking. But I guess I have an earlier year rear axle. I am going to call Mazdatrix tomorrow and see about shipping this one back or getting an earlier year flange.

Also is this gap in the picture between the driveshaft and transmission normal? It's when it's "bolted" to the diff.

The u-joints on the old one are done for they don't move freely and it's starting to make a bassy rumbling noise at certain speeds.

 

You have an early rear end because of the threaded flange. I thought the early drive shafts were rebuildable. Even the 84/85 drive shafts are rebuildable. Search for staked drive shaft. Cost me just over $100.

 

Sooo the older driveshafts work in the 84 transmission? That really sucks I should of done more research but I gotta learn somehow haha.

Well now I have a brand new driveshaft with easily replaceable u-joints but I just need an earlier flange, which I can't find on Mazdatrix. Hopefully they have them and I can order one over the phone.

 

What happened to the old drive shaft?

 

Bad u-joints but I was unaware that I had the earlier year rear axle so I didn't know I could just rebuild it.

 

Get the old one rebuilt and you might be able to send the new one back.