Some classic metal bands have been forced to replace their guitarists. These were not easy decisions to make, but they were necessary for continuing on, much like becoming a forgotten band. Luckily, though, they avoided that distinction.

In many cases, these forced changes happen due to conflict within the group. Sometimes issues get so bad that there is no choice but to go separate ways. However, there are instances where the reasons are more morbid. Either way, it doesn't make these decisions easier, especially when they only find a replacement for one album. Nonetheless, even those brought in to be transitional pieces play a major role in a band's history.

10 Dio

Vivian Campbell - Craig Goldy

After finding success in a few bands, including replacing Ozzy Osbourne in Black Sabbath, Ronnie James Dio decided to start his own band, which would go by his name, Dio. Along with himself, he would recruit a drummer, bass player, and guitarist, Vivian Campbell. For the first few albums, things seemed to be great as the band found major success.

With songs like "Holy Diver" and "Rainbow in the Dark," the band became one of the premier metal groups. However, things weren't as great behind the scenes as Campbell was becoming restless. After many disputes, it was decided that it was best for Campbell to leave the band. This turned out to work for him, as he would later become a key member of the hit-making Def Leppard.

9 Thin Lizzy

Snowy White - John Sykes

Throughout the 12 studio albums that Thin Lizzy produced, they went through multiple guitarists, but arguably their most devastating departure was when Snowy White left the band. He was only with them for two albums, in 1980 and 1981, but then he was gone. The problem was that they still wanted to produce a final record.

They not only got their final studio album recorded, but Sykes helped make it one of their heaviest sounding ever.

Since the band's environment didn't align with what White wanted personally, he wasn't coming back. Therefore, they had to bring in John Sykes. This turned out to be a great decision, as they not only got their final studio album recorded, but Sykes helped make it one of their heaviest sounding ever, making this short-lived recording team a success.

8 Deep Purple

Ritchie Blackmore - Steve Morse

One of the founding of Deep Purple was guitarist Ritchie Blackmore. While the band struggled early on to find a consistent lead singer, Blackmore did not help the situation when he first left in the mid-1970s. He would then go on to form the band Rainbow, which experienced some success, before taking a hiatus in 1983.

It was during this hiatus that Blackmore would return to the reformed Deep Purple and stay until 1993. He would leave again due to internal differences. This time, he would be replaced by Steve Morse, who went on to have a nearly 30-year tenure with the band. As difficult as it was to see a founding member leave the group twice, they ultimately did get it right with Morse, who more than filled his role.

7 Megadeth

Marty Friedman - Al Pitrelli

As a guitarist who experienced a notable exit from Metallica, Dave Mustaine wanted to prove he could stand on his own with his band Megadeth. Unfortunately, in the band's first three albums, they went through two guitarists before finding Marty Friedman. He would stay with them for the next four albums, which included Rust in Peace and Countdown to Extinction.

Unfortunately, prior to the 2001 record, Friedman left the band due to personal reasons and a desire for more creative freedom. In no position to slow down, Mustaine was able to bring in Al Pitrelli to fill in for the next record. Although his time with the band was short, it was vital, as it kept their momentum going.

6 Motörhead

"Fast" Eddie Clarke - Brian Robertson

As Motörhead began their rise in the late '70s, guitarist "Fast" Eddie Clarke was there for all of it. He contributed to all of their early albums, including two of their biggest, Overkill and Ace of Spades. The trio composed of him, Lemmy, and Phil "Philthy Animal" Taylor became an iconic group, but it wasn't meant to last, as Clarke would leave in the midst of the promotion for the Iron Fist record.

Clarke's exit stemmed from major disagreements with his bandmates over the production of the Iron Fist album. After his departure, the band had no intention of slowing down, so they recruited former Thin Lizzy guitarist Brian "Robbo" Robertson. He served his purpose and helped them through the making of Another Perfect Day before the band would find other players to .

5 Dokken

George Lynch - Reb Beach

Throughout their early career, Dokken experienced many highs and lows. The band made a significant name for themselves, but at one point in the late '80s, they would part ways. Eventually, the band would end up back together. However, the turmoil didn't stop there. Within just a few short years, one of their founding , George Lynch, would exit the band.

Unfortunately, Lynch and lead singer Dave Dokken didn't see eye to eye at that time. Their internal conflicts proved to be too much. To keep their recording plans on track, the band brought in Reb Beach, who rose to fame in the band Winger. With Beach, they recorded one album, Erase the Slate, which was enough to keep them on course.

4 Judas Priest

K.K. Downing - Richie Faulkner

In their historical career, there isn't much that Judas Priest hasn't experienced. After starting as more of a blues rock band, they switched their sound to focus on heavy metal. This change paid off tremendously, and they became early pioneers of the new wave of British heavy metal. They became one of the biggest bands in the genre, surviving everything, including lead singer Rob Halford leaving for years.

Another tumultuous chapter in their history occurred in 2011 when one of their founding , K.K. Downing, exited the band. There was a lot that Downing was disappointed about. His relationship with his bandmates and their management broke down. This left a significant gap to fill, but now three albums in, guitarist Richie Faulkner has held his own.

3 Mötley Crüe

Mick Mars - John 5

In the 1980s, perhaps no band was bigger than Mötley Crüe. Through their first five albums, they produced many hits, and it seemed that nothing could slow them down. Unfortunately, as they entered the '90s, things weren't as smooth. Their lead singer, Vince Neil, would leave for one album before returning for another. Then, drummer Tommy Lee would leave the group.

Ultimately, Lee found his way back into the band, and as they have aged, they have continued to work on projects such as their Netflix film, The Dirt. While the other three have persevered, guitarist Mick Mars has had to slow down due to his health. The group decided to bring in John 5. Although it seemed the split was amicable, Mars claims it wasn't and continues to seek a resolution.

2 Iron Maiden

Dennis Stratton - Adrian Smith

One of the most famous musician replacements in history belongs to Iron Maiden when they brought in lead singer Bruce Dickinson for their third album, The Number of the Beast. However, before this occurred, there was another significant change that they decided to make. Guitarist Dennis Stratton appeared on their self-titled debut record, but this is the only album he would be part of.

Instead of working through the issues, they opted to bring in Adrian Smith to replace him.

The primary reason Stratton didn't mesh well with the band was a clash of personalities. Instead of working through the issues, they opted to bring in Adrian Smith to replace him. Although he left for a period of time during the '90s, he is still with them today. He has proven to be a fantastic addition to the group, and he has become one of their iconic faces.

1 Ozzy Osbourne

Randy Rhoads - Jake E. Lee

When Ozzy Osbourne's time with Black Sabbath was over, he decided to start his own band, which would bear his name. Although Osbourne was in a tough spot, he and his bandmates created magic with their debut album, Blizzard of Oz. A fantastic sophomore record, Diary of a Man, would follow. However, during the tour for this record, tragedy struck as guitarist Randy Rhoads died in an aviation accident.

This was a devastating situation, but the band decided the show must go on. While they found temporary replacements to fulfill their live show obligations, they would eventually make a permanent move by bringing in Jake E. Lee. For the next two albums, Lee would contribute his unique style to the band, but it was never easy, as he had a tough act to follow.