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Good evening folks,
I'm looking to reinstall the stock rubber bushings into the diff cover/carrier. Anyone have a technique that worked for them? i plan on starting with a big c-clamp and not anticipating an issue but ya know how that goes. And can someone confirm they press in from the front facing the rear of the crossnember? All my research leads to that and they seem to get a better start in that position.
Thanks for any help
Good evening folks,
I'm looking to reinstall the stock rubber bushings into the diff cover/carrier. Anyone have a technique that worked for them? i plan on starting with a big c-clamp and not anticipating an issue but ya know how that goes. And can someone confirm they press in from the front facing the rear of the crossnember? All my research leads to that and they seem to get a better start in that position.
Thanks for any help
I had tracdogg2 install some poly bushings in my Dana 44. He had to use a press to get them in. I hope yours are easier. I believe he started them from the front.
I was starting to think that no one attempted this. i read up that putting them in the freezer overnight contracts the metal some and to lubricate the housing. i have a 2 ft. heavy duty c-clamp i'm gonna start with, most likely with a breaker bar towards the end. 2nd option is a grade 8 nut, bolt and impact gun and pull it in. Any other thoughts or ideas are welcome. Going to attempt it this week, ill let ya know.
Thank
Svette, nice looking ride. Cant wait to replace my avatar when i get wheels on the ground.
Can't remember which way they went in from but I think if you look closely you'll see that they will only go in all the way from one direction. I can confirm later when I get into work. I used a press to install mine.
Yes they install from the front. Upon a closer look there is an indent in the housing on the batwing which corresponds with an outdent on the bushing. Gonna play with it this week.
So the 1st attempt with the c clamp failed due to the screw extending too far and bending. In its defense i took a phone call 3/4 of the way in and left the pressure on it. When i resumed it bent. Next attempt with the bolt and washers, pulling it in went nowhere also. Wound up purchasing a 21 piece ball joint press and it went in with ease. Heavy duty clamp and screw with plenty of attachments and I can use it for other bushing replacements. I would recommend it if you don't have. EBAY of course. However between the width of the housing and bushing, i needed another 3/4in receiving tube as the others are 2 and 2 1/4. Went to auto zone and rented another kit at no charge.
They're in and next step, attaching the differential with new 354:1 gears.
I went from Dana 3.08 to 3.54 as well. I love the additional off the line feel and plan to eventually add a 5th gear to eliminate the high RPMs at highway speed.
That was and is the concern when i switched but had the same mindset with the 5th gear. Won't know until i get it motoring but wanted to bump it up some and figured i would start there while i had the rearend out. What kind of high RPM's at highway speed can i expect?
That was and is the concern when i switched but had the same mindset with the 5th gear. Won't know until i get it motoring but wanted to bump it up some and figured i would start there while i had the rearend out. What kind of high RPM's at highway speed can i expect?
Where did you buy your bushings? Did you also replace the front cushion along with the two batwing mounts? I’m gearing up to do this over the winter on my 1982.
I bought the end bushings and the upper and lower cushion from mid america as I wanted the OE rubber and they were always reputable. For some strange and unknown reason, they only had 1 end bushing in stock and i had to wait about a month for the 2nd 1. If you search other suppliers or ebay you can find them somewhat cheaper. However I am so disgusted by the new parts that i'm receiving, this time the upper cushion, that i searched ebay for a NOS and purchased that. The lower bushing was acceptable. The lower bushings in the photos are the NOS.
Are you going rubber or poly? I have no experience with poly so I stayed OE.
I did this project about 2 years ago on my 81. I went from rubber to poly since they were easier to install and the rubber ones were hard to find. Most Vette parts houses carry only the poly.
First step, drill out the old rubber bushing by drilling a bunch of holes all the way around. Some people have used a hole saw too. The rubber core will come out easily afterwards. Then take a hack saw apart and reassemble with the blade going through the hole. This step will allow you to cut a score line on the remaining metal bushing. Be careful you do not cut into the aluminum, but deep enough to almost go all the way thru. Next step use a chisel and hammer to collapse the metal sleeve and it will pop out.
The new poly bushings do not require a metal sleeve and will slide in very easy into the batwing holes after applying the silicone lube for poly bushings and the center metal sleeve.
It does seem like a lot of places do only carry the poly. I have read that for the differential, poly bushings do not absorb enough of the energy during hard shifts/acceleration, etc, to prevent damage to the frame and supports.
81vettski: I want to replace everything with OEM rubber, as it was from the factory. My alignment shop told me the my front cushions were totally disintegrated (which explains the loud clunk when shifting). I have read that to get rubber bushing that fit, something has to be drilled out when installing replacements. Was that required in your case? I haven't been able to find any NOS stuff on ebay, just the new rubber replacements that claim to work for all 68-82 models, which some have said differ after 1980.
I did my rear end in all poly except the long bolt cushions that adjust the spring height. There was poly installed from the previous owner, but they were old and cracking. The batwing poly bushings do stiffen things up more and you can hear a little more road noise through the suspension into the frame, but should be much more more stress than with a new pair of rubber bushings. Why would all of the Vette suppliers carry only the poly for the batwing then?
I am in the process of replacing all of my front end suspension and in this case though went back to OEM rubber since I am not going to track the car and was told by my alignment shop the rubber bushings in front will hold the alignment much longer and give a better feel in steering, not too harsh. Rearend was not a concern.
I too chose to use poly bushings in the batwing itself but rubber everywhere else when rebuilding my rear end. From what I've been told the tongue hole of the differential itself has to be enlarged to accept the current reproductions that are available, but I swear I bought mine a year or so ago and don't recall any fit issues on my '80. I can't recall at this point who my supplier was for that bushing, but I certainly hope all was installed properly as I found it impossible to replace that bushing without lowering the entire differential! (Which luckily I was doing anyway as part of my full rearend upgrade.)
Hey G. In addition to my research there was a thread on here about a broken tongue on the frame from poly bushings. I have not installed the differential yet as its getting checked out after sitting for quite some time after the rebuild. Seems the bearing and seals dried out a bit. If you go on the Wilcox site, tech and install help under rear suspension, it does say the tongue on the diff has to be enlarged. I don't understand why. If you look at the attached photo, the tabs on the NOS and part from Mid America are the same size. Maybe its the part they sell? I am not anticipating a problem but will certainly let you know. If you search for the upper cushion you are looking for GM part# 14010397.
Reaper. I hate to be cynical but I think cost has a lot to do with the parts we are all receiving these days. Maybe its evolution. I stayed OE rubber cause i have no experience with poly and figured i can't go wrong with it. Good to hear about the rubber for the front but thats in the distant future. May have to pick your brain with the rest of my rearend build.
81Vettski it seems a lot of vendors have pushed poly as being the best upgrades for your car, whether the front end or rear end, trans and engine bushings, everything. A lot of the talk is for better handling and tracking your car. I have a friend in our corvette club that rebuilt his 68 and upgraded his suspension and every piece of the car including all Poly bushings everywhere. It does ride harder, but handles great. Whenever I go to car shows everyone with classic cars have mostly done the same to achieve better handling.
You bring up a good point though about the batwing and stress from the stiffer contact points. Luckily when I rebuilt my rear end bushings I dropped my rear end since the front seal was leaking. Instead of rebuilding the diff I bought a diff and batwing from another 81 owner that had his car totaled in the front. His rearend was just rebuilt by Duntov for 550HP with hardened axles, other upgrades and 3.08 gears. The cost was cheaper to by the whole setup than have mine rebuilt. I do have my original rearend and batwing sitting in the corner of my garage with original rubber bushings in case I need it in the future or do some other upgrades.
Hopefully the poly bushings being sold were tested properly in our C3's and the scenarios being discussed were taken into consideration or there will be a lot of broke wings in the future.
Maybe one of the vendors or engineers that created the batwing Poly bushings will chime in with some more information.
Good luck with your rebuild. I would be glad to help when you start rebuilding your front end. Mine was all original, rotors, bushings springs etc. I am replacing mostly everything brakes included, except items like spindles, stamped control arms etc. But all bushings are going back to original rubber, except the stabilizer bushings.
09-17-2017, 12:01 AM
81 batwing bushings
A lot of the talk is for better handling and tracking your car. I have a friend in our corvette club that rebuilt his 68 and upgraded his suspension and every piece of the car including all Poly bushings everywhere. It does ride harder, but handles great. Whenever I go to car shows everyone with classic cars have mostly done the same to achieve better handling.