» Site Navigation | | » Recent Threads | | | | | | | 03-01-2006, 10:19 AM | #1 | Senior Member Join Date: Jun 2003 Location: San Jose, CA, USA Posts: 253 | e30 Diff Swap Well, I picked up an e30 325is diff today, although I can't really get started until the engine's done. Here's the first pic: http://www.318ti.org/gallery/showgallery.php?cat=600 First things I'm seeing here: 1. The output shafts' flanges' holes are indeed further apart than the stock unit. I assume this is where swapping flanges comes in. 2. The input shaft is about 1 cm longer than the 'ti unit as measured to the front mounts. This is not good, I really didn't want to worry about the driveshaft not fitting. 3. The distance across the diff from output shaft to output shaft is about 3 cm longer. This jives with the e30 halfshafts being shorter; I've seen some botched jobs before where the wrong lengths of halfshaft were used and all kinds of problems happened. I think I'll start by looking at the e30 halfshaft distance and see if that makes up for the difference; that would make this easier. I'm still a little worried about #2 above, however. Hmm... __________________ Andy Chittum - Mad Man Motorsports | | | 03-01-2006, 07:03 PM | #2 | Senior Member Join Date: Sep 2004 Location: Manassas, VA Posts: 4,129 | Andy I've been waiting for more info on this dilemma for awhile. I have an E30 diff to put in too. Here is my question. What is the flange to flange width of the E30 diff with 318ti flanges, and what is the flange to flange width of the 318ti diff with 318ti flanges? I plan on putting in the E30 diff with 318ti flanges, and wanna know how much extra width, if any , there will be. That issue with the drive shaft concerns me. I haven't heard anyone complain about that being an issue. Eric Quote: Originally Posted by andy Well, I picked up an e30 325is diff today, although I can't really get started until the engine's done. Here's the first pic: http://www.318ti.org/gallery/showgallery.php?cat=600 First things I'm seeing here: 1. The output shafts' flanges' holes are indeed further apart than the stock unit. I assume this is where swapping flanges comes in. 2. The input shaft is about 1 cm longer than the 'ti unit as measured to the front mounts. This is not good, I really didn't want to worry about the driveshaft not fitting. 3. The distance across the diff from output shaft to output shaft is about 3 cm longer. This jives with the e30 halfshafts being shorter; I've seen some botched jobs before where the wrong lengths of halfshaft were used and all kinds of problems happened. I think I'll start by looking at the e30 halfshaft distance and see if that makes up for the difference; that would make this easier. I'm still a little worried about #2 above, however. Hmm... | __________________ 1998 (July) 318ti, 5-spd OEM Armrest Blaupunkt Heidelberg CD50 CD Player/Compact Drive MP3 Player Diamond Audio 5.25" rear speakers Navman ICN 530 GPS BMWALARM.COM (with comfort settings) after market alarm system Magnecor 8.5mm wires M-Z3 Shifter/Momo Knob Burlwood Dashboard Stromung Exhaust X-brace Racing Dynamics Front Strut Bar Carbonio C.A.I. 17" Rial Rims Vader Seats/Heated/Lumbar Support M-tech Steering Wheel/Front Sway Bar/Front & Rear Bumper Depos/w 6500K Angel Eyes/6000K HIDs Clear Corners M3 Mirrors UUC Light Weight Flywheel/M5 Clutch/M3 Clutch Slave E28 3.46 LSD/Mcoupe Cover/E30 Flanges & Halfshafts UUC S.S. Brake/Clutch Lines Hartge Roof Spoiler BavAuto Springs Bilstein Sport Struts/Shocks E46 M3 Rear Shock Mounts SPC Front Camber Kit Reiger Hatch Spoiler BavAuto Rear Camber Kit Dinan Stage II Software Turner Rear Sway Bar Reinforcements BMW E46 Auto dimming mirror with Clown Nose alarm Engine Compartment Light Heated Wiper Fluid Retrofit OEM Fire Extinguisher Da'lan Trailer Hitch Rear Sun Shade OEM Fog Light Retrofit H & R MZ3 Rear Sway Bar/ UUC Adjustable End Links Cruise Control Retrofit On Board Computer Retrofit M3 twistie style side skirts Carbon Fiber Hood | | | 03-01-2006, 10:10 PM | #3 | aka Stabby Join Date: Nov 2004 Location: Mead, CO Posts: 5,336 | notice the ti diff cover extends further back? you'll likely need to "make" a little room in the rear subfloor beam to clear the top of the diff cover, but other than that, it's no problem. i believe the ti flanges extend out less than the e30 flanges, which is why the swap of flanges and using the ti halfshafts appears to work. that said, i swapped to e30 flanges and halfshafts. i'd be interested to hear if the person was able to swap in the m-coupe halfshafts with no issues. never did hear ... __________________ 1996 318ti, California package, 267k miles current mods: bilstein sports, bavauto springs, e30 m3 LCABs, solid metal ball joints, bavauto RSMs w/reinforcements, e30 3.73 LSD & halfshafts, supersprint cat-back exhaust, turner rear sway bar reinforcements, IE poly subframe & RTABs + camber/toe kits, powdercoated e36 32x front calipers, sport mirrors, H&R 28mmF/19mmR sway bars, x-brace, auto solutions SSK w/poly bushing upgrade, BMW CD43 head unit, DICE HD Radio w/iPod integration and "stealth" HD antenna, staggered style 68s, orange electronic TPMS, leather arm rest, JT Designs metal undertray acquired and awaiting install: heated seat kit, cali top switch relo, lumbar support kit, park distance control kit, heated washer nozzle kit, m-coupe rear subframe, trailing arms, differential, and halfshafts, m-coupe front/rear brakes with master cylinder, under hood light kit, mud flaps, rear sun blind, auto-dimming rear view mirror, tilt steering wheel retrofit, apexcone 5000K HIDs with 55W ballasts 2002 X5 4.4 Sport Package, 53.5k miles Current Mods: e46 m3 steering wheel | | | 03-01-2006, 10:16 PM | #4 | Member Join Date: May 2005 Location: So Cal Posts: 70 | What is the total benefit of doing this? I'm not too savvy on LSD's and ratio's and all that | | | 03-01-2006, 10:34 PM | #5 | aka Stabby Join Date: Nov 2004 Location: Mead, CO Posts: 5,336 | higher ration (3.45 -> 3.73) results in quicker acceleration (and a 10% increase in revs turned at the same speed). typical benefit is getting limited slip as almost all the ti's came with open diffs. the e30 diff can also handle more power (large case diff coming from a e30 325). __________________ 1996 318ti, California package, 267k miles current mods: bilstein sports, bavauto springs, e30 m3 LCABs, solid metal ball joints, bavauto RSMs w/reinforcements, e30 3.73 LSD & halfshafts, supersprint cat-back exhaust, turner rear sway bar reinforcements, IE poly subframe & RTABs + camber/toe kits, powdercoated e36 32x front calipers, sport mirrors, H&R 28mmF/19mmR sway bars, x-brace, auto solutions SSK w/poly bushing upgrade, BMW CD43 head unit, DICE HD Radio w/iPod integration and "stealth" HD antenna, staggered style 68s, orange electronic TPMS, leather arm rest, JT Designs metal undertray acquired and awaiting install: heated seat kit, cali top switch relo, lumbar support kit, park distance control kit, heated washer nozzle kit, m-coupe rear subframe, trailing arms, differential, and halfshafts, m-coupe front/rear brakes with master cylinder, under hood light kit, mud flaps, rear sun blind, auto-dimming rear view mirror, tilt steering wheel retrofit, apexcone 5000K HIDs with 55W ballasts 2002 X5 4.4 Sport Package, 53.5k miles Current Mods: e46 m3 steering wheel | | | 03-01-2006, 10:43 PM | #6 | Member Join Date: May 2005 Location: So Cal Posts: 70 | so, if my '97 (most likely) has the open diff, I would benefit from getting a LSD for my car which would be an easy bolt on direct replacement and a good mod? Hmmmm... I may have to find one of these "LSD"'s you speak of... | | | 03-01-2006, 10:54 PM | #7 | aka Stabby Join Date: Nov 2004 Location: Mead, CO Posts: 5,336 | the only TRUE easy, direct bolt-on, no issues LSD is the 3.45 LSD from the 95 (and i believe early 96) ti's that had it or, it appears, m42/44 z3's that again might have had it. it was even an option for automatics, but that gives a higher ratio, 4.44. __________________ 1996 318ti, California package, 267k miles current mods: bilstein sports, bavauto springs, e30 m3 LCABs, solid metal ball joints, bavauto RSMs w/reinforcements, e30 3.73 LSD & halfshafts, supersprint cat-back exhaust, turner rear sway bar reinforcements, IE poly subframe & RTABs + camber/toe kits, powdercoated e36 32x front calipers, sport mirrors, H&R 28mmF/19mmR sway bars, x-brace, auto solutions SSK w/poly bushing upgrade, BMW CD43 head unit, DICE HD Radio w/iPod integration and "stealth" HD antenna, staggered style 68s, orange electronic TPMS, leather arm rest, JT Designs metal undertray acquired and awaiting install: heated seat kit, cali top switch relo, lumbar support kit, park distance control kit, heated washer nozzle kit, m-coupe rear subframe, trailing arms, differential, and halfshafts, m-coupe front/rear brakes with master cylinder, under hood light kit, mud flaps, rear sun blind, auto-dimming rear view mirror, tilt steering wheel retrofit, apexcone 5000K HIDs with 55W ballasts 2002 X5 4.4 Sport Package, 53.5k miles Current Mods: e46 m3 steering wheel | | | 03-01-2006, 11:08 PM | #8 | Senior Member Join Date: Dec 2005 Location: Asheville NC Posts: 669 | hmmm... thinking... hmmm... I have a 3.73 LSD from an e28 (same as e30 except for rear cover) sitting in my garage, how is drivability with that gear ratio in our cars? | | | 03-02-2006, 01:14 AM | #9 | Member Join Date: Jul 2005 Location: LA Posts: 37 | Quote: Originally Posted by CaliDohBoy so, if my '97 (most likely) has the open diff, I would benefit from getting a LSD for my car which would be an easy bolt on direct replacement and a good mod? Hmmmm... I may have to find one of these "LSD"'s you speak of... | Easy? I have an e30 lsd, while using my ti halfshafts and flanges. Getting the old diff out was a pain in the @$$ because those freaking top bolts are hard to access and were covered in 10 years of dirt. Also, make sure you have that torx socket!!! Sure you can use a hex socket, but you'll probably end up rounding off some of the bolts like I did. Also, since the diff is bigger, I had to pound in some of the metal so it would sit flush. | | | 03-02-2006, 01:20 AM | #10 | Senior Member Join Date: Jun 2003 Location: San Jose, CA, USA Posts: 253 | I'll get some exact measurements in the next few days. I'm going to be racing in the US Touring Car race at Laguna Seca (A1GP Support Race - woo hoo!) on 3/10-12, so I've got a few other details to take care of. I'll try to keep this as updated as possible, though. The thing about the drive shaft was measured from the front mounts to the end of the driveshaft. It's not that much different, there might be enough slack to just jam it in, but I'm really going to be whomping on this thing, so I don't want it to go bad prematurely. But interesingly, even though the case is differently sized the rear diff plate does seem to be pretty close to the right place. The width of the output shafts is interesting as well. From the pic, both diffs' output shafts are pretty flush. The interesting thing is comparing the two to my '91 318is - it has a small case diff and huge flanges sticking out several inches. e30s, I think use all the same length shafts, while e36s seem to vary. I may be cruising for Z3's to measure out there, but I'm heading to the junk yard tomorrow morning... Oh, and I'll start another thread on gear ratios, there are some interesting things about that too. Yes, in general BMWs and particularly those with semi-trailing arms work great with an LSD, whether it be track or autocross, or driving on a slippy road. __________________ Andy Chittum - Mad Man Motorsports | | | 03-02-2006, 01:27 AM | #11 | Senior Member Join Date: Sep 2004 Location: Manassas, VA Posts: 4,129 | When you say the to flanges stick out less than the e30 flanges, are you saying with both flanges in a ti diff? That is what I can't get a straight answer on. I'm only interested in knowing the flange to flange width of an e30 diff with the stock flanges and also the ti flanges. Quote: Originally Posted by cali-ti i believe the ti flanges extend out less than the e30 flanges, which is why the swap of flanges and using the ti halfshafts appears to work. | __________________ 1998 (July) 318ti, 5-spd OEM Armrest Blaupunkt Heidelberg CD50 CD Player/Compact Drive MP3 Player Diamond Audio 5.25" rear speakers Navman ICN 530 GPS BMWALARM.COM (with comfort settings) after market alarm system Magnecor 8.5mm wires M-Z3 Shifter/Momo Knob Burlwood Dashboard Stromung Exhaust X-brace Racing Dynamics Front Strut Bar Carbonio C.A.I. 17" Rial Rims Vader Seats/Heated/Lumbar Support M-tech Steering Wheel/Front Sway Bar/Front & Rear Bumper Depos/w 6500K Angel Eyes/6000K HIDs Clear Corners M3 Mirrors UUC Light Weight Flywheel/M5 Clutch/M3 Clutch Slave E28 3.46 LSD/Mcoupe Cover/E30 Flanges & Halfshafts UUC S.S. Brake/Clutch Lines Hartge Roof Spoiler BavAuto Springs Bilstein Sport Struts/Shocks E46 M3 Rear Shock Mounts SPC Front Camber Kit Reiger Hatch Spoiler BavAuto Rear Camber Kit Dinan Stage II Software Turner Rear Sway Bar Reinforcements BMW E46 Auto dimming mirror with Clown Nose alarm Engine Compartment Light Heated Wiper Fluid Retrofit OEM Fire Extinguisher Da'lan Trailer Hitch Rear Sun Shade OEM Fog Light Retrofit H & R MZ3 Rear Sway Bar/ UUC Adjustable End Links Cruise Control Retrofit On Board Computer Retrofit M3 twistie style side skirts Carbon Fiber Hood | | | 03-02-2006, 01:29 AM | #12 | Member Join Date: May 2005 Location: So Cal Posts: 70 | I understand the E30 diff is not an "easy" install... but what about E36 diffs from the ti's that came with them as Cali-ti pointed out? What would the 4.44 ratio do to my automatic? | | | 03-02-2006, 01:42 AM | #13 | aka Stabby Join Date: Nov 2004 Location: Mead, CO Posts: 5,336 | Quote: Originally Posted by L84THSKY When you say the to flanges stick out less than the e30 flanges, are you saying with both flanges in a ti diff? That is what I can't get a straight answer on. I'm only interested in knowing the flange to flange width of an e30 diff with the stock flanges and also the ti flanges. | no, the ti flanges in the e30 diff stick out less than the e30 flanges in the e30 diff as shown by dredder: http://318ti.org/forum/showthread.php?t=7865 the ti halfshafts are longer than the e30 halfshafts and the e30 diff is wider than the small case diff in the ti. as long as you have no issue with the strength of the ti flanges and halfshafts, i see no reason why it shouldn't work. __________________ 1996 318ti, California package, 267k miles current mods: bilstein sports, bavauto springs, e30 m3 LCABs, solid metal ball joints, bavauto RSMs w/reinforcements, e30 3.73 LSD & halfshafts, supersprint cat-back exhaust, turner rear sway bar reinforcements, IE poly subframe & RTABs + camber/toe kits, powdercoated e36 32x front calipers, sport mirrors, H&R 28mmF/19mmR sway bars, x-brace, auto solutions SSK w/poly bushing upgrade, BMW CD43 head unit, DICE HD Radio w/iPod integration and "stealth" HD antenna, staggered style 68s, orange electronic TPMS, leather arm rest, JT Designs metal undertray acquired and awaiting install: heated seat kit, cali top switch relo, lumbar support kit, park distance control kit, heated washer nozzle kit, m-coupe rear subframe, trailing arms, differential, and halfshafts, m-coupe front/rear brakes with master cylinder, under hood light kit, mud flaps, rear sun blind, auto-dimming rear view mirror, tilt steering wheel retrofit, apexcone 5000K HIDs with 55W ballasts 2002 X5 4.4 Sport Package, 53.5k miles Current Mods: e46 m3 steering wheel | | | 03-02-2006, 01:45 AM | #14 | aka Stabby Join Date: Nov 2004 Location: Mead, CO Posts: 5,336 | Quote: Originally Posted by CaliDohBoy I understand the E30 diff is not an "easy" install... but what about E36 diffs from the ti's that came with them as Cali-ti pointed out? What would the 4.44 ratio do to my automatic? | if you can find a ti or 1.8/1.9 z3 auto that had a LSD (again, this is a small case diff), it will bolt right in with no issues (and be the same 4.44 ratio as your current automatic open diff). it's going to a large case diff where you run into fitment issues (although not too big of issues). __________________ 1996 318ti, California package, 267k miles current mods: bilstein sports, bavauto springs, e30 m3 LCABs, solid metal ball joints, bavauto RSMs w/reinforcements, e30 3.73 LSD & halfshafts, supersprint cat-back exhaust, turner rear sway bar reinforcements, IE poly subframe & RTABs + camber/toe kits, powdercoated e36 32x front calipers, sport mirrors, H&R 28mmF/19mmR sway bars, x-brace, auto solutions SSK w/poly bushing upgrade, BMW CD43 head unit, DICE HD Radio w/iPod integration and "stealth" HD antenna, staggered style 68s, orange electronic TPMS, leather arm rest, JT Designs metal undertray acquired and awaiting install: heated seat kit, cali top switch relo, lumbar support kit, park distance control kit, heated washer nozzle kit, m-coupe rear subframe, trailing arms, differential, and halfshafts, m-coupe front/rear brakes with master cylinder, under hood light kit, mud flaps, rear sun blind, auto-dimming rear view mirror, tilt steering wheel retrofit, apexcone 5000K HIDs with 55W ballasts 2002 X5 4.4 Sport Package, 53.5k miles Current Mods: e46 m3 steering wheel | | | 03-02-2006, 02:34 PM | #15 | Senior Member Join Date: Sep 2004 Location: Manassas, VA Posts: 4,129 | I think I misspoke. What I want to compare is the width flange to flange of the stock diff with stock flanges, to an E30 diff with ti flanges. Isn't that the only comparison that matters. I wanna know if the E30 diff with ti flanges is wider than stock setup. If it is, that could be a big problem. From what everyone says, the swap is no problem. Quote: Originally Posted by cali-ti no, the ti flanges in the e30 diff stick out less than the e30 flanges in the e30 diff as shown by dredder: http://318ti.org/forum/showthread.php?t=7865 the ti halfshafts are longer than the e30 halfshafts and the e30 diff is wider than the small case diff in the ti. as long as you have no issue with the strength of the ti flanges and halfshafts, i see no reason why it shouldn't work. | __________________ 1998 (July) 318ti, 5-spd OEM Armrest Blaupunkt Heidelberg CD50 CD Player/Compact Drive MP3 Player Diamond Audio 5.25" rear speakers Navman ICN 530 GPS BMWALARM.COM (with comfort settings) after market alarm system Magnecor 8.5mm wires M-Z3 Shifter/Momo Knob Burlwood Dashboard Stromung Exhaust X-brace Racing Dynamics Front Strut Bar Carbonio C.A.I. 17" Rial Rims Vader Seats/Heated/Lumbar Support M-tech Steering Wheel/Front Sway Bar/Front & Rear Bumper Depos/w 6500K Angel Eyes/6000K HIDs Clear Corners M3 Mirrors UUC Light Weight Flywheel/M5 Clutch/M3 Clutch Slave E28 3.46 LSD/Mcoupe Cover/E30 Flanges & Halfshafts UUC S.S. Brake/Clutch Lines Hartge Roof Spoiler BavAuto Springs Bilstein Sport Struts/Shocks E46 M3 Rear Shock Mounts SPC Front Camber Kit Reiger Hatch Spoiler BavAuto Rear Camber Kit Dinan Stage II Software Turner Rear Sway Bar Reinforcements BMW E46 Auto dimming mirror with Clown Nose alarm Engine Compartment Light Heated Wiper Fluid Retrofit OEM Fire Extinguisher Da'lan Trailer Hitch Rear Sun Shade OEM Fog Light Retrofit H & R MZ3 Rear Sway Bar/ UUC Adjustable End Links Cruise Control Retrofit On Board Computer Retrofit M3 twistie style side skirts Carbon Fiber Hood | | | | | Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | | Posting Rules | You may not post new threads You may not post replies You may not post attachments You may not edit your posts HTML code is Off | | | |